E. S. Greiner observes rod of boron powder
being melted by floating-zone refining.
This technique has produced boron crystals
as large as 0.1 inch across (see p. 476).

the eventual equipment or sysiem he hopes
to produce. A way to hasten the process
of engineering development is to

the many techniques contributing to the de-
sign and ultimate effectiveness of modern mili-
tary systems. This technique is used, for example,
in grounded flight trainers where student pilots,
through simulation, learn the conditions and sen-
sations occurring in actual flight. Another example
is the simulated flight conditions found in a wind
tunnel, where engineers study the aerodynamic
forces on aircraft and missile structures.

: (RECORD, February, 1959), a large number of
actual field tests have been performed. For this
program, however, there are limitations, both
physical and financial, that prevent engineers
from completing a large number of intercepts
under the same conditions. By simulation, they
can “perform,” quickly and cheaply, enough en-
gagements between simulated missiles and targets
to get conclusive results. Thus evolved the Nike
system tester, used to simulate the various Nike
guided missile systems over the past ten years.
During this period the tester has carried out
more than 70,000 realistic engagements.

Over the vears, engineers have found a good
correlation between the results of the actual in-
tercepts and the simulated engagements for sim-
ilar conditions. Such agreement, of course, helps
them to trust the results of the simulation of
other factors, such as targets of the future. Simu-
lation also permits controlled testing situations
where a whole series of engagements are carried
out under precisely the same conditions. The
value of a single parameter can be changed be-
tween successive tests so that the effect of that
factor only can be evaluated. This, of course,
would be impossible in a real operating system.

Like most other major military developments,
the Nike guided missile systems employ simula-
tion in a variety of forms. General and special-
purpose digital and analog computers at the
Laboratories, the White Sands Missile Range in
New Mexico and the Douglas Aircraft Company
in Santa Monica, California, have been in con-
tinuous use solving problems peculiar to the mis-
sile, the radars, and the guidance, as well as

Simulation equipment room at the Whippany,
New Jersey, location of the Laboratories. Part
of guidance computer can be seen on left wall.
Across front, B. R. Burrell, left, and D. L. Castner
make adjustments to target and radar portion of
simulator. J. N. Wright sits at console where
initial conditions of a simulated engagement are
set into the system. To right of area shown
in picture is the missile portion of simulator.

combinations of these major components. When
the characteristics of the components are incor-
porated in a complete system simulator, such as
in the Nike system tester, designers can make
an over-all evaluation of the system by simulation
in the laboratory, well in advance of system tests
in the field.

To understand how it can help insure the suc-
cess of a military weapon, perhaps we should
first recall what simulation is. Simulation may
be defined as a representation of a physical device
by any means that generates an equivalent result.
A well-known example is the use of electrical
networks to study or measure mechanical sys-
tems. Here, engineers use the analogy between
mechanical and electrical systems to transform
the physical quantities of one system into those
of the other.

Simulation may contain some components actu-
ally used in the physical system as well as some
simulated components. On the other hand, all
components may be simulated —a type usually
referred to as mathematical simulation. A device
of this type is, in reality, an equation solver. The
best known of these are the digital computers

Set-up of Nike system tester is quite similar to
that of a regular weapon system. Target, missile

which solve equations describing a physical sys-
tem and generate answers a physical system
would produce.

What are the reasons for using simulation in
the development of military systems, as well as
in civilian activities? First of all, the compli-
cated nature of many components and the system
they comprise make it impractical and at times
impossible to compute, by normal calculating
methods, their performance characteristics and
to study the effects of various parameters.

For example, during the early stages of the
development of a weapon system it may not be
possible to predict accurately the characteristics
desired of various components, although their
general characteristics and limitations may be
known. Circuits which smooth radar tracking
data, for instance, can suppress spurious fluctua-
tions in the data, but at the expense of intro-
ducing a time lag in transmitting the data. By
including such circuits, either in physical or
simulated form, in a system simulator, engineers
can study the effect of component variations on

and computer are tied together by radar sig-
nals. Computer system functions on “real” time.

system performance. Simulation for this purpose
may be considered as a design tool.

The philosophy for the family of Nike guided
missile systems is to employ a “command type”
of missile control — orders to steer the missile
to intercept the target are generated by ground
equipment and transmitted to the missile. Fur-
thermore, insofar as possible it employs proven,
or reasonable extensions of, available techniques.
By this procedure, development time is minimized
and the expendable part of the system — the
missile — is kept as simple as possible.

A Nike system was! first simulated with a
so-called “computer analyzer’ —a simple, two-
dimensional electronic simulator containing many
approximations to the final Nike system. Bell
Laboratories engineers used the computer an-
alyzer to confirm the analytically derived method
of operation for Nike, and to establish optimum
values of some of the important constants of the
system. The value of simulation such as this,
even if simplified, is illustrated by the fact that
subsequent field operations and more complete
simulation have not modified the basic conclu-
sions derived from the computer analyzer.

The computer analyzer was a forerunner of the
Nike system tester, a three-dimensional device
which has been in operation at the Whippany,
New Jersey, location of Bell Laboratories for
about ten years. This special-purpose, large-scale
simulator for Nike systems employs analog com-
puting equipment to simulate the characteristics
of major components significantly affecting the
performance of the system.

The Nike system tester performs both the de-
sign-tool and evaluation functions mentioned pre-
viously. Its major sections include the guidance
computer and simulation of the missile, radars,
and, of course, a target.

The only major component not simulated in the
tester is the guidance computer. This is a physi-
cal component that operates as part of a field sys-
tem. The arrangement is such that the computer
doesn’t know whether the problem it’s solving is
a real or a simulated one, and thus performs in an
identical manner in either case. For this reason,
the tester operates on a “real time’”’ basis.

However, the target, missile, and radar sections
employ mathematical simulation since their input-
output characteristics need only reproduce the
performance of physical components. This is justi-
fied, because in studying the performance of a
system it is not necessary to simulate the actual
internal mechanisms of a component, but only a

The“computer analyzer’’—simple two-dimensional
electronic simulator — forerunner of Nike tester.

In the study of a component, however, engineers
would normally simulate the internal mechanism
when they study the component itself. Douglas
Aircraft Company engineers, for example, simu-
late the Nike missiles and their internal control
systems, including the effects of aerodynamic re-
actions on the missiles and their control surfaces.

In undertaking simulated engagements, the
Nike system tester goes through the same opera-
tional sequences as would a field system. The
target is started on its course, and at the proper
time the missile is launched. The missile proceeds
through its normal boost and motor-burning
phases and the guidance system automatically
guides it to intercept the target.

At the start of the engagement, the initial con-
ditions of the target and missile — their position,
heading and speed — are pre-set into the simu-
lator. In the case of the missile these conditions
are the position of the launcher on the ground,
its attitude in the launcher and zero velocity.
Thereafter, the system continuously computes

positions in space by adding to these initial posi-
tions the integrated velocities and accelerations as
they occur during the engagement.

The accelerations that produce speed changes,
in either target or missile, are the result of longi-
tudinal thrust and drag forces. On the other hand,
transverse accelerations produce course changes
and these accelerations are usually considered
as target or missile maneuvers. These quantities
of position, velocity, acceleration and many others
are represented in the simulator by accurately
and properly scaled voltages.

The missile and target sections of the simulator
are normally used as part of the closed loop sys-
tem in which the missile is automatically steered
by the guidance computer. The missile and target
simulator sections, however, may be operated in-
dependently as trajectory calculators without au-
tomatic guidance. They also may operate either
with or without programmed accelerations ap-
plied during flight.

As indicated in the block diagram on page
448, the section representing the target can pro-
duce the characteristics and maneuvers of both
aircraft and ICBM type targets. The maneuvers
— simulated changes in course and speed — may
continuously vary or may be introduced discretely
in steps. Two sources of the “stepping” maneu-
vers are an integral part of the system. One is a
programmer in which 38 separate maneuvers in
each of two channels may be stored to be applied
to the target selectively during its “flight.” The

R. M. Hangley, left, and V. M.
Cousins with the data record-
ing machines. The continuous
pen recorder, behind Mr. Hang-
ley, keeps track of such fune-
tions as steering orders to the
missile and “time to intercept.”

other is a function generator that uses teletype-
writer tape to store maneuvers. This can produce
an unlimited number of discrete orders in each of
three control channels at a rate of five per second.

The missile section of the simulator continu-
ously computes the effects of thrust, drag and lift
forces as a function of the environment the mis-
sile encounters during flight. This includes the
effects of variation of the mass of the missile as
its fuel is consumed and the variation of its re-
sponse to steering orders as a function of such
things as changes in speed and altitude.

In addition to pre-setting initial engagement
conditions, operators can simulate a wide range
of missile types, or variations of a given missile
characteristic. They do this by setting simple
potentiometers by hand to establish such charac-
teristics as the mass of a missile, its wing area,
and the magnitude and duration of its booster and
motor thrust. This arrangement is an important
design tool because with it, engineers can deter-
mine by successive trials the best value of a given
chara teristic. The effects of many such charac-
terstics defy normal types of analysis.

In a field system, the radar data transmitted
to the computer, which define the apparent posi-
tions in space of the target and missile, would
contain unavoidable errors. These come from the
dynamic characteristics of the radars, and spuri-
ous fluctuations in the radar data called “tracking

noise.” In the Nike system tester, however, the
position data produced by the target and missile
simulator sections are, by definition, the true posi-
tions of target and missile in space, and as such
are error free.

To simulate the effect of radar errors, the true-
position data to the computer are passed through
networks that simulate the dynamic errors of the
radars. Also, simulated noise errors are gener-
ated and fed to the computer along with the radar
data. The computer then operates as though the
primary radar data contained the radar errors.
However, the true target- and missile-position
data are free of errors for the measurement of
their true positions in space.

Probably the most important data obtained
from an engagement, either actual or simulated,
is the magnitude of the “miss distance’ — the
positions of target and missile in space at the
instant the warhead explodes. The tester obtains
the miss distance by accurately measuring the
positions of target and missile at the instant the
computer generates the burst signal.

A considerable amount of additional data is
recorded during each simulated engagement. An
automatic data recording system converts from
analog to digital form voltages representing 25
of these important quantities and automatically
types the data on a form sheet.

A bank of continuous pen recorders makes rec-
ords of 42 quantities of a similar nature. Further-
more, two plotting boards record the trajectories
of the target and missile throughout each engage-
ment, one giving the ground projection of the
paths, and the other a view in the vertical plane.
Although the continuous pen recorders are only
moderately accurate, the data they record gives
an excellent qualitative picture of the situation
existing during each engagement. These data are
also valuable in indicating and locating equipment
troubles.

Although a valuable tool, simulation has cer-
tain inherent deficiencies which would be present
in anything short of a complete physical system
operating under field conditions. Simulation does
not, for example, shed much light on the reliabil-
ity of the field equipment, since the Nike system
tester includes a limited amount of equipment
identical to that used in the field system. Further-
more, any such equipment contained in the simu-
lator is maintained and operated by Beil System
specialists under controlled conditions.

On the other hand, simulation contains its own
class of errors, such as mistakes made by the
operators as well as the designers, and possible
equipment troubles. A burden is thereby imposed
on the simulator designers. They have to ensure
that the characteristics of the physical system,
including all discernible sources of error, are
properly simulated, and that spurious errors gen-
erated by the simulator itself are minimal.

A good measure of the adequacy of a system
simulator is obtained by duplicating the firings of
a physical system, and comparing the results in
detail. This method has been employed through
field test programs involving the firing of a con-
siderable number of Nike missiles. Some of the
simulated firings duplicated those of the field sys~
tem and demonstrated very good correlation of
results. For this reason, engineers are highly con-
fident in the results they have obtained from the
simulator under conditions they could not attain
at a missile proving ground.

One of the important assets of the Nike tester
type of simulation is its ability to obtain a meas-
ure of the performance of the missile system
while it is still in a conceptual stage. After simu-
lating its proposed characteristics, and those of
the targets, engineers conducted tests to show up
required changes early in development. ae

The Nike system tester employs standard ana-
log computer techniques. The major electronic
elements include operational amplifiers that per-
form the mathematical operations of adding, in-
tegrating and differentiating and a number of
special devices such as function-generators and
multipliers. Electromechanical servomechanisms
use precision wire-wound potentiometers RECORD,
May, 1954) to generate highly accurate voltages
as functions of other voltages. The tester con-
tains 270 operational amplifiers and 28 servos.

Insofar as possible, the Nike system tester uses
standard computer components, at times modified,
and special equipment only where the standard
equipment is not suitable. The tester is a special-
purpose device with a relatively fixed arrange-
ment of its circuits. This presents an advantage
in design whereby those areas requiring high
accuracy justify a large amount of time and effort
to achieve the required accuracy; in the areas re-
quiring less accuracy, design effort is minimized.
The various parts of the simulator are thus tai-
lored to meet specific requirements, and vary in
accuracy from one in 20,000 to one in 20.

The age of electronics is now actually
invading our coat pockets. New and improved
equipment has recently been installed by
Ohio Bell Telephone Company, assisted by
Bell Laboratories, to offer a personal
signaling service. This service, in effect,
enables a customer to carry his telephone
bell around with him wherever he goes.

Personal Signaling is essentially an extension
of the bell on a customer’s telephone. It operates
in such a manner that any customer to the service
absent from his phone can be signaled “selec-
tively” to indicate that he is wanted. That is, of
the customers using the service, he alone hears
the signal. He may then go to the nearest tele-
phone and call a predetermined number to obtain
the message. For this service, a radio transmitter
sends coded signals corresponding to the cus-
tomer’s number. These signals are picked up by

pocket-size radio receivers carried by the cus-
tomer. Each receiver is responsive to a particular
code, which when received, causes an audible
signal to sound and alert the customer.

The Columbus installation, in contrast to the
earlier installation in Pennsylvania, permits calls
to be handled directly from the telephone switch-
board using substantially standard operating
techniques. It is also arranged to operate on and
share the same radio channel with a general
mobile-telephone system. With the present limited
frequency spectrum available to the common-
carrier mobile telephone services, such dual oper-
ation of two services on a single radio channel
will be of considerable advantage.

The Personal Signaling system installed in
Columbus is indicated in the first block schematic.
Shown in this figure are both the Personal
Signaling system and the mobile-telephone sys-
tem with which it is integrated. This mobile-
telephone system operates from the switchboard

through a control terminal, a base-station trans-
mitter, and several base-station receivers. Per-
sonal Signaling service operates from the same
switchboard through a signaling control terminal
and a separate radio transmitter. An interlock-
control circuit, shown in the center of the dia-
gram, interconnects the mobile-telephone and per-
sonal-signaling systems.

Both systems operate in the 30 to 44 mc band,
and the signaling system uses the same fre-
quency as that transmitted from the mobile-
telephone transmitter—namely, 35.42 me.
Though it would be desirable to use the same
transmitter for both services, this was not
possible in Columbus. The reason is that the
mobile-telephone service uses frequency modula-
tion and the available pocket receivers were
designed for amplitude modulation. Thus, it was
necessary to use a separate AM radio transmitter
for the signaling service.

The equipment is arranged to transmit per-
sonal signals whenever the radio channel is not
in use for mobile telephone service. This is
achieved with an interlock control circuit. This
circuit accepts a request for the radio channel
from the signaling control terminal and assigns
the signaling transmitter to it if there are no
mobile telephone calls in progress. When the
channel is busy, transmission is delayed until
the end of the existing mobile-telephone call. If
personal signals are being transmitted, the in-

terlock circuit also prevents completion of a
mobile-telephone call until the signaling call in
progress is completed. When the channel is re-
quired for both services, telephone and personal
signaling calls are transmitted alternately. Since
a signaling call is always of very short duration,
this in effect gives priority to the mobile tele-
phone service.

Each signaling code is made up of four tones
transmitted sequentially. These are chosen from
nine available tones in the frequency range from
about 160 to 300 cycles per second, each of which
corresponds to a digit between one and nine.
Aside from certain unusable codes, the maximum
number of codes available is approximately 3500.

The total time required to transmit a code is
1.4 seconds. To insure reception of the signal,
each code is transmitted three times with an
interval between codes of approximately 2.5
seconds. Thus, the time required to transmit a
complete signal is about 9 to 10 seconds. Since
another period of about 2.5 seconds is required
between signals, the system can handle up to
about 300 calls per hour — assuming that the
radio channel is not in use during any of that
time for mobile-telephone service.

We note in the first diagram that the Personal
Signaling service is operated from a switch-
board over either of two standard operator

system (PSS) and general mobile-telephone serv-
The circuits include both the personal signaling

Signaling control terminal used for personal sig-
naling service. Incoming signals from the switch-

trunks which terminate in the control terminal.
A block schematic of this terminal is shown in
the second diagram. The equipment is mounted
on a standard channel-type relay rack (right side
of photograph opposite) and is located beside the
control terminal.

As seen in the diagram above, after a call is
stored in a register, the signaling control circuit
gives an indication to the interlock circuit. If
the radio channel is idle, or as soon as it becomes
available, this latter circuit returns an indication
to the signaling control circuit to start the
transmission of signals. After assurance that
the radio transmitter is radiating its carrier,
the stored pulses in the register are translated
to the four-tone signal. The four tones obtained
from the tone generator are transmitted through
the transmitter control circuit and over a trunk
to the radio transmitter. After the four-tone
signal is sent out three times, it is removed from
the register. If another code is stored in the
second register or, when one is received from
the switchboard, the interlock circuit is inter-
rogated, and the new signal is transmitted as
soon as the radio channel becomes idle.

Only one transmitter control circuit is used
for the Columbus installation, since in this case
only one radio transmitter is employed for the
signaling system. However, the control terminal
has been designed to function on an optional

board, in the form of dial pulses, are translated to
tone signals and passed on to the radio transmitter.

basis with a number of transmitters or groups
of transmitters. These may be energized in
turn to prevent false signaling of receivers which
might otherwise be located in areas of over-
lapping transmitter coverage.

To meet FCC requirements, the signaling con-
trol terminal contains a station identifier and
timing circuit. This circuit functions with the
other equipment to connect identifying tone
signals — consisting of the call letters of the
radio station in international Morse code — to
the transmitter trunk 30 minutes after the first
personal signal is sent out, or as soon thereafter
as the radio channel becomes available. The
identification signal is also radiated three times.
Following the next transmission of a signaling
code, a new timing cycle is started. The station
identification signal is thus repeated about every
30 minutes as long as the signaling system is
in operation.

The signaling control terminal also includes
a test and supervisory circuit containing cir-
cuitry for supervising, monitoring and testing
the entire system. These functions are aided
with a test panel which contains a dial and hand-
set, together with a number of keys and super-
visory or trouble lamps.

Personal signals pass from the signaling con-
trol terminal over a short cable circuit to the
radio transmitter. This circuit is arranged to
give two dc paths for controlling and supervising
the transmitter remotely.

The AM transmitter has a power output of
250 watts, and is located on the 42nd floor of a
tall building in the central part of Columbus. The
antenna system is also placed on this building.
It includes two antennas (half-wave coaxial
dipole types) mounted on diagonally opposite
corners on building offsets in such a manner that
the tips of the antennas are approximately 480
feet above street level, but about 70 feet lower
than the top of the building tower. The antennas
are energized simultaneously and in phase to
reduce distortion because of the shielding and
reflection effects of the tower.

Pocket radio receivers used in the Columbus
system are the same as those employed in the
Allentown installation. Each is a self-contained,
completely transistorized unit which measures
1-14 by 2-36 by 5-% inches and weighs about 8
ounces. The receiver is powered by replaceable
mercury cells capable of operating it for approxi-
mately 750 hours.

A super-regenerative type of receiver is used.
The audio-frequency part of the circuit includes
four tuned reeds operating in the frequency
range from 160 to 300 cycles per second. When
these reeds vibrate in proper sequence in response
to an incoming signal, an audio-frequency oscil-
lating circuit is energized. The output of this
circuit is connected to a minature loudspeaker
which operates to alert the customer until he
presses a button on the receiver.

Because of the inefficient, internally contained
antennas necessarily employed with pocket re-
ceivers, the radio signal required to operate them
is some 20 to 30 db higher than that required for
satisfactory operation of a mobile telephone in-
stallation on a vechicle. Consequently the area
over which personal signals can be received from
a given transmitter is considerably less than that
ordinarily expected in a vehicular communication
system. In addition, this area is further restrict-
ed when the customers are in shielded areas such
as automobiles or buildings.

The territory in and around Columbus is rela-
tively flat, and a favorable location for the an-
tenna system was available on a tall building.
The accompanying map indicates the area over
which signals can be received when customers
are in automobiles or on streets. The circle with

a radius of 3.5 miles from the transmitter out-
lines the boundary for the reception of signals
when customers are in automobiles, when they
are carrying receivers on their persons, and
when the receivers are of just acceptable sensi-
tivity. Some receivers, however are somewhat
more sensitive. The circle having a 6.0 mile radi-
us indicates the signaling area for customers, in
automobiles, with receivers that have maximum
sensitivity.

Much greater range is possible when the cus-
tomers are in the open. This is indicated by the
12-mile circle within which customers using re-
ceivers of minimum required sensitivity can be
signaled when they are on city streets. On the

Signaling control terminal is mounted on a stand-
ard channel-type relay rack (right), and is located
beside the control termine! (left), which is in turn
associated with the mobile-telephone system.

Map showing the transmitter location in down-
town Columbus, Ohio. Circles indicate areas with-
in which customers in automobiles and on the
city streets can receive the radio-beamed signals.

other hand, our tests have indicated that, under
favorable circumstances, persons in the open with
receivers having maximum sensitivity can be
signaled up to distances as great as 17 miles.

The signaling range in buildings has not been
thoroughly investigated in Columbus, but data
obtained from this and other locations indicate
that under these circumstances, ranges from
about 0.5 to 8 or 9 miles may be obtained, depend-
ing on the type of building.

Determining the effects of sharing a radio
channel with mobile-telephone services was an
important task at Columbus. The primary advan-
tage of such operation is, of course, more effi-
cient usage of the radio spectrum. On the other
hand, operating the two services on the same
channel has its disadvantages.

One important disadvantage is that when
channel time is shared, the number of customers
which can be served by the signaling system is
considerably reduced. Small delays for calls of
both types are also encountered. In addition,
there is a possibility that mobile customers may
be confused as they attempt to place calls when
the signaling system is busy, since they will hear
the signaling tones.

The personal signaling system was placed in
operation in Columbus on May 1, 1958, with
some 40 pocket receivers in service. After four
months, the number of receivers in use had in-
creased to about 120. During this period, there
was an average of 85 mobile-telephone units

using the radio channel. For each business week
from 8:00 a.m. to 5:00 p.m., Monday through
Friday, the radio channel was used by these units
for mobile-telephone service about 38 per cent of
the time. The delays on these ‘mobile calls’ are
extremely short.

However, to assist in determining the effects of
sharing the radio channel by the two services,
the significant delays experienced by the ‘signal-
ing calls’ during the initial service period have
been recorded and analyzed. For the four-month
period, no delay was experienced by 57 per cent of
the signaling calls. The average delay for the
other 43 per cent was 1.6 minutes, and less than
6.5 per cent of all the calls were delayed more
than 3 minutes.

Further information of this type — along with
other plant, traffic and commercial studies —
will be required to determine the performance of
the integrated signaling system. However, ex-
perience in Columbus indicates good public ac-
ceptance of the service. We now know that opera-
tion of a signaling system on the same radio
channel with a mobile-telephone system is both
feasible and desirable.

Author wearing in vest one of the pocket re-
ceivers used in the Columbus system. Each re-
ceiver is a self-contained unit weighing about
eight ounces. It is powered by replaceable mer-
cury-cell batteries that last about 750 hours.

The optical microscope serves the
metallurgist in three important ways: in
the development of new materials; in
showing changes in the structure of metals
with time; and in furthering man’s research
into a fundamental understanding of

Not so long ago, metallurgy might have been
defined as “the art of extracting metals from
their ores and preparing them, alone, or in the
form of alloys, for the service of man.” From
Tubal Cain, the worker in brass mentioned in the
Old Testament, and beyond, the history of the art
is a long one, and may be said to parallel closely
the later course of man’s own history.

Metallurgy began to change from an art to a
science about 100 years ago. It was then that the
Englishman, H. C. Sorby, applied the optical
microscope to the study of the structures of steel.
Sorby and his successors laid the groundwork of
what is now physical metallurgy. Other valuable
tools for the study of metals have been developed
in recent years. But the optical microscope, now
often an elaborate instrument equipped with many
helpful accessories, still remains among the most
useful and indispensable tools of the metallurgist.

The first great triumph of Sorby and his imme-
diate followers was an approach to an understand-
ing of the reasons why carbon steels of iden-
tical chemical composition could be given widely
varying physical properties by changes in heat
treatment. In addition to arriving at a clearer
understanding of the practical aspects of making
steel of high quality, these pioneer microscopists
made important collateral strides in metallurgi-
cal theory. To do this, they borrowed ideas from
studies of chemical equilibria and applied them
to metallurgical equilibria.

An important basic concept transferred was
that of “phase” — as used in the area of physical
chemistry then being studied by the American,
J. Willard Gibbs (1839-1903), and the Hollander,
Bakhuis Roozeboom (1854-1907). By applying
this concept, the study of alloys has been sys-
tematized. The results of these studies have been

made readily accessible in the form of “constitu-
tional,” “phase” or “equilibrium” diagrams. Such
a diagram represents the phases, liquid and solid,
which form in alloys under different conditions
of concentration of components and of tempera-
ture. They also show limits of existence of the
phases under certain ideal circumstances. To-
gether, these ideal circumstances make up a state
formally described as “thermodynamic equilibri-
um,” and they derive from established laws of
chemistry. Gibbs’ Phase Rule, which describes
the conditions for thermodynamic equilibrium,
is one of the most important of these laws.

The importance of the phase concept to metal-
lurgy lies in the fact that the kinds of phases
present and their form and distribution are re-
sponsible for many of the differences in the
physical properties of alloys. The era of rapid
progress in the science of metallurgy which fol-
lowed the adoption of the phase concept found the

In practical alloying, true thermodynamic equi-
librium is seldom achieved — for good reasons.
Sometimes, it takes too critical processing or too
iong a time. In other cases, a state of incomplete
equilibrium may be deliberately sought to obtain
some especially desired physical property, such as
great hardness. However, the constitutional dia-
gram still has immense value in tailoring an alloy
to a particular need.

All metals, when melted together, influence
each other’s “personality,” even if they only in-
teract to the extent of dissolving one in the other.
This solution-forming tendency may, and usually
does, persist into the solid state. Several solid
solutions may be possible, and even exist simul-
taneously in an alloy system. Other phases that
may form are those akin to intermetallic com-
pounds, or solutions of these.

A familiar example of a simple solid solution
is cartridge brass, often termed “alpha brass.”
This alloy contains about 30 per cent zinc dis-

Constitutional diagram of the binary alloy system
of aluminum-copper. As the very small and very
irregular areas in certain portions of the plot
show, even a binary alloy can produce many and

60 70 80 90 100
ALUMINUM
complex phases. As some of the area designations
indicate, certain portions of the alloy are made up
of two phases. This diagram was taken, with minor
changes, from the Metals Handbook, 1948 Edition.

solved in 70 per cent copper. If the alloy has been
subjected to suitable mechanical and heat treat-
ments, the zine will be uniformly distributed
through the copper, diluting its red color to the
familiar yellow of brass. A plane section, properly
polished and etched, looks the same under the
microscope as all elementary metals and homoge-
neous solid solutions.

The metal’s “landscape” will be featureless ex-
cept for a network of lines, which are called
“grain boundaries.” In three dimensions, the
surfaces corresponding to these lines enclose the
grains — the building blocks of the gross metal
structure. Grains are occasionally called “crystal
grains” or “crystallites,” reminding us that while
they do not possess the plane faces and sharp
edges of the familiar concept of crystals, they are
nevertheless internally crystalline and are com-
posed of atoms sited in orderly array.

While most elementary metals and simple solid
solutions possess relatively simple internal struc-
tures, some solid solutions may have internal
structures of considerable complexity. Conse-
quently, their “space lattices” — a characteristic
described in detail later — have a low order of
symmetry so that these complex structures pos-
sess a low degree of “give” under stress and are
brittle. The presence of one or more brittle phases
can make an alloy commercially useless. Examples
of brittle compositions exist even in the brasses
and in the copper-tin system — the bronzes.

To illustrate the complexities in phase-inter-
relationship and the possibilities of structural in-
homogeneity which may result even in a binary,
or two-metal, system, let us consider aluminum-
copper. The constitutional diagram for this sys-
tem is shown at the left. The complexities indi-
cated in the diagram may be still further com-
pounded by a condition of incomplete equilibrium.
In the diagram, the letter “L” represents the
liquid phase while the Greek letters denote the
different solid phases, and the lines bound the re-
gions of their existence and co-existence.

To the experienced metallographer, the complex
of phases present in an alloy, similar to those
indicated by the phase diagram, are apparent
from microscopic investigation. For example, the
low-power micrograph (a) at the top of page 460
shows a section of a bead formed by first twisting
together a copper and an aluminum wire and then
melting the twisted ends with a spark. The time
for interaction between the metals was thus very
short. The phases formed were of varying degrees
of brittleness, and at the slightest pull the wires
tended to break off from the bead. In many simi-
lar samples, the stress set up by cooling in the

different phases was sufficient to cause rupture,
because each phase has a characteristic rate of
thermal contraction.

This sectional area of the bead shows that sev-
eral phases, indicated by differences in reactivity
to chemical etchant, had formed in succession. At
the extreme lower right is the structure of the
copper of the unmelted wire. The next area,
toward the left, is copper which has rapidly melt-
ed and re-solidified. Then follows a series of
aluminum-copper phases successively richer in
aluminum, ending with the large area of highly
aluminum-rich material at the left and above.
The dark formations here are gas holes.

Details of a portion of the area in this micro-
graph are given in the companion illustration (b),
taken at appreciably higher magnification. Here,
the different phases are more clearly delineated.
This micrograph was taken after hardness tests
of different parts of the multi-phase area had
been made, which accounts for the different-sized
square markings with diagonals. Each of these
squares corresponds to an indentation made by a
diamond penetrator, each time loaded to the same
degree. From the areas of the squares, the rela-
tive hardness of the individual phases can be
computed. The smaller squares of course corre-
spond to the harder phases. This micro-hardness
technique, an auxiliary to metallurgical micro-
scopy, is becoming increasingly useful in the study
of the micro-constituents of structure.

The optical microscope, therefore, clearly asso-
ciated the physical behavior of the beads of alumi-
num-copper alloy with the complexities of phase
formation characteristic of the system. These
complexities were increased by the lack of time
available to attain some reasonable degree of
thermodynamic equilibrium. This and other diffi-
culties temporarily prevented the development of
what appeared to be a simple, effective and eco-
nomical method of joining copper wires to alumi-
num wires in the Bell System telephone plant. A
different approach later solved the problem.

An equally graphic illustration of the profound
structural differences possible within an alloy,
still of only two metals, is shown by the two
micrographs (c and d) in the middle of page 460.
The alloy is copper — 2 per cent beryllium, slight
modifications of which find increasing and im-
portant application in present-day engineering.
The two samples represented were cut from ad-
joining areas of the same ingot, and were suitably
polished and then chemically etched to bring out
surface detail.

The complex structure at left (c) is of the alloy
in the “as cast,” or nonequilibrium, condition.
Three phases are present. The predominant light
phase is the background, or “‘matrix,” phase which
consists of a solid solution of beryllium in copper.
As one might guess from its appearance, this solid
solution is not here homogeneous. The alloy is
generally not used in the form shown because its
properties are correspondingly non-homogeneous.
The accompanying micrograph (d) shows the
same alloy after it was subjected to a single heat
treatment: heating for some hours at 800°C and
quenching or cooling rapidly. This treated alloy is
still generally undesirable commercially because
of the presence of the white, beta phase. The dark
phase is called gamma. Hence, the microscope
shows directly and graphically, and in a way that
is easy to interpret and explain, the ineffective-
ness of a particular heat treatment.

The properties of copper —2 per cent beryl-
lium can be improved, however, because this alloy
is of a class called “age-hardenable.” Desirable
physical properties are obtained by carefully con-
trolled heat treatments, usually two. The exact
temperatures and times of these must be worked
out experimentally.

Briefly, the alloy is first heated at an elevated
temperature to insure a complete solid solution
of the beryllium in copper. It is then quenched to
room temperature. It is now supersaturated with
respect to beryllium and will remain so because
at this temperature the rate of precipitation of
dissolved material is exceedingly slow. Therefore,
a second heat treatment, at an intermediate tem-
perature, is required to precipitate out the ex-
cess of dissolved beryllium. This precipitate is
not elementary beryllium itself but the gamma

Micrograph (a), taken at low power (40x), is of a
section of a metal bead formed in joining a copper
wire to an aluminum wire by a spark. Micrograph at
higher power (265x) (b), illustrates hardness of
various areas measured by a diamond penetrator. In
the center are photomicrographs (135x) of an alloy
of copper and 2 per cent beryllium. Complex struc-
ture (c) is the material in the “as-cast” condition,
and the more homogeneous structure (d) is the same
material after heat treatment. Bottom pair of micro-
graphs (67x) show cable sheath believed to be of
Western Electric manufacture (e) compared to
known, standard Western lead-antimony sheath (f),
used throughout the Bell System. When further com-
pared, the two proved to be of the same origin. These
micrographs and those on pages 462 and 463 were
taken by the author. Magnifications are approximate.

phase already mentioned. The separation takes
place in somewhat the same way as ice particles
appear during the cooling of regions of the upper
atmosphere. Some mechanical treatment may be
added to facilitate the first heat treatment.

Most of the metallurgical work done with the
microscope is far removed from the romanticism
of scientists in white coats pontificating over
deadly microbes. Occasionally, however, one’s de-
tective instinct may find some expression in work-
ing back from a microstructure to the cause of
some apparent oddity of behavior of a metal. This
might be done by tying that behavior in turn to
some departure from best practice in fabrication.

Also, since so many alloys look superficially
alike, it may be necessary to obtain not only posi-
tive identification of some material but some idea
of its history. For example, the micrograph (e)
at the bottom left of the group opposite repre-
sents the structure of a lot of lead-alloy cable
sheathing which had strayed illegally from Tele-
phone Company possession and whose identity
was important to establish beyond doubt. The
structure was thoroughly familiar to the micro-
scopist as that of Bell System cable-sheathing
alloy, lead —1 per cent antimony, with certain
characteristics ascribable to a service life of some
years. It corresponded almost exactly with the
structure of a sample taken from service else-
where, shown adjacent (f). The identification was
further confirmed by spectrochemical analysis and
by certain structural features associated with
Western Electric methods of fabrication.

Another interesting problem in “practical” met-
allurgy, solved with the help of the microscope,
concerns the metal “cards” for the card translator
in the No. 4A toll switching system (RECORD,
March, 1955; May, 1955; August, 1955). The card
translator, which is an automatic card file of
available alternate routes for direct-distance-
dialed toll calls, contains about 1000 cards made
of strip steel, hard-rolled. Over the steel there is
a protective plating of nickel, over which is
“flashed” a thinner coat of chromium.

In normal operation, the cards are pulled up
by magnets and dropped very rapidly —up to
several times per second. To make them flat
enough to do this smoothly, a stress-relief anneal
was necessary. In some cases, however, the an-
nealing, though it made the card generally flatter,
increased (up to 30 per cent) rather than de-
creased the interface friction.

A look at sections of some lots of the translator
cards under the microscope revealed that the in-
creased roughness was due to “cannibalistic”
growth of some of the crystal grains of the nickel

plate at the expense of others. In the series of
micrographs below, the untreated card metal, as
received from the supplier, is shown on the left.
The middle one shows a satisfactorily annealed
strip with the columnar grain structure of the
nickel recrystallized but without unduly large
grains. The right-hand micrograph shows the
large cannibalistic grains that resulted in the
nickel layer from annealing at too high a tempera-
ture. This, in turn, resulted in a corresponding
localized roughness in the chromium layer.

Crystal grains of metals, when studied micro-
scopically, can thus tell the metallurgist a great
deal about the surface of the metal. But the fun-
damental significance of grains and boundaries
goes much deeper. Some reference has already
been made to the internal structure of elementary
metal grains and of simple homogeneous solid
solutions. These structures consist of atoms in
orderly array. If we were to join these individual
atom sites, whose distance apart and arrangement
are now well known through X-ray studies, by
imaginary lines, we would obtain “lattice” struc-
tures repetitive in three dimensions throughout
the grains. 2

The various forms of lattices for the elemen-
tary metals are few, are fairly simple, and pos-
sess high orders of symmetry. One of the most
valuable properties of metals —the capacity to
be usefully shaped by deformative processes —
derives partly from this lattice symmetry. Metals
can be bent, spun, extruded or otherwise formed
because a relatively large number of atom-plane
systems are available for slipping or sliding past

one another, as in a deck of cards, while still re-
taining a high degree of adherence to each other.

The theory involved in this simple assumption
is insufficient to account for the whole story of
metallic behavior, however. For example, calcu-
lations of the strengths of metals made on the
basis of lattice perfection give values up to a
thousand times greater than the actual measured
values. Other facts concerning metal structures,
difficult to explain on such simple grounds, are
the details of plastic deformation and the equally
complex details concerning the growth of crystals.

In an attempt to explain the mechanical be-
havior of metals, many theories concerning lat-
tice defects have been postulated over the last
twenty years. One class of lattice imperfections
is called “dislocations,” and important contribu-
tions to Dislocation Theory have been made at
Bell Laboratories by W. Shockley, W. T. Read,
Jr., F. L. Vogel and others (RECORD, March, 1955;
August, 1955; April, 1956).

Dislocation Theory has made a number of suc-
cessful predictions. One was the existence of a
certain type of dislocation, the so-called “edge
dislocation.” The more specific corollary predic-
tion was that a “boundary” between two very
slightly misoriented, neighboring regions in an
otherwise perfect single crystal should be made
up of a linear array of edge dislocations, equally
spaced.

“Etch pits,” frequently seen in metals, have
long been associated with the presence of either
particles of impurity or of otherwise highly local-
ized areas of high potential energy. Such special

Photomicrographs of cross-section of three differ-
ent cards, shown here at about 1000. The light
area at the top is steel, the slightly irregular area
immediately below the steel is nickel, and the fine
light line below this is the outside chromium lay-
er. Black area at bottom is a bakelite block used to
mount cards for photography. Card on left is as re-

ceived from supplier, with no heat treatment. Mid-
dle card has been satisfactorily stress-annealed
without appreciable grain growth in the nickel. The
card at the right has also been annealed, but at too
high atemperature, so that fewer and larger grains
have developed in the nickel layer and these have
distorted the very thin surface layer of chromium.

Etch pits in germanium. Such microstructures
indicate the existence of edge dislocations.

regions tend to etch chemically at rates faster
than their immediate surroundings, and pitting
results. Occurrence of arrays of discrete, equally
spaced pits might then correspond to equally
spaced linear arrays of edge dislocations.

Were there to be such a correspondence, dis-
creteness of the pits — that is, a sufficient degree
of optically visible separateness under the micro-
scope at reasonable magnification — would be ob-
tainable if the degree of misorientation were
small enough and the etching carefully controlled.
The first micrograph of a series of etch pits def-
initely identified with a corresponding array of
edge dislocations is shown in the micrograph
above. The small but accurately determinable
value of angular misorientation of the two ad-
jacent portions of crystal, calculated from direct
optical measurement of the pit spacing, was com-
pared with that found by x-ray measurement.
Agreement was very close.

The high-purity, single-crystal material used
in this experiment was germanium, which had
been previously examined in the course of in-
specting similar samples for use in transistors.
Many subsequent experiments of the same type,
with different materials, have gained wide ac-
ceptance for the reality of edge dislocations. This
in turn has given added credence to other aspects
of general dislocation theory.

The microscope work of the Metallurgical Re-
search Department thus ranges from problems
that arise in alloy development or are associated
with details of fabrication by Western, to those
of basic research into the structure of metals.

Dr. J. B. Fisk — President of the Laboratories
— has again been named to serve as chairman of ©
a group of U. 5S. scientists currently participating
in nuclear test talks with Soviet scientists. Ac-
cording to Secretary of State Christian A. Herter,
the new taiks concern the latest scientific data
applicable to detection of underground nuclear
tests. The meetings again are being held in Geneva.

The earlier talks, held during the summer of
1958, were also on the technical aspects of policing
a nuclear test ban. The new talks began the week
of November 23. The U. S. group includes severa.
members of the original 1958 technical conference.

In addition to his career at Bell Laboratories,
Dr. Fisk also served as Director of Research of
the Atomic Energy Commission for two years.
During that time he also was Gordon McKay Pro-
fessor of Applied Physics at Harvard University.
He is currently a member of The President’s
Science Advisory Committee and a member of
the General Advisory Committee of the Atomic
Energy Commission.

being subjected to an intensive program of
studies. New coin mechanisms and modern
techniques promise to make the well

known public telephone an even more
attractive, efficient and useful instrument.

Some time during the coming year the total
number of public telephones in the Bell System
will reach one million. This millionth coin-oper-
ated telephone may be installed in an outdoor
booth, a “drive-up” booth, an indoor unit, or on
the wall of a business or public establishment.
It will symbolize the great extent of this type
of service, which, except for the war years, has
been growing continuously. This growth record
is evidence that public telephones serve the Amer-
ican public well and produce sufficient revenue
for the Operating Companies to warrant con-
tinued studies directed toward further improve-
ments in service.

The first major post-war improvement in coin
telephones was a new coin chute, introduced in
1947. This new chute was given a high priority
when it became evident that rapidly rising costs
would require higher basic rates for coin service.
Other changes in the familiar design included
a push button for clearing out coins, and a “‘pull-
bucket” arrangement for the refund opening.

It was long recognized that other improve-
ments should be introduced in the coin telephone.
The basic instrument and circuit had its origin
in the early days of telephony, and many of the
mechanisms and circuits were designed for meth-
ods of manufacture and operation existent at

that time. The post-war development effort per-
force was directed toward necessary immediate
modification of the existing plant, and did not
satisfy the need for an over-all new design. More

Details of the “read-in” portion of the new coin
totalizer. Basic operation is to rotate totalizer
shaft in proportion to amount of deposit. Rate
can be adjusted by repositioning cam at left.

The author demonstrating an appearance model of
the new design coin telephone. External appear-
ance of coin unit was styled by Henry Dreyfuss.

recently, therefore, a complete re-evaluation of
all parts of coin telephone apparatus and opera-
tion has been undertaken.

The systems, transmission and apparatus
problems of providing public telephone service
have now been studied intensively. This effort
resulted in the development and construction of
laboratory models of coin telephone apparatus
containing many new features. These devices and
circuits were assembled in an exploratory coin
telephone and were placed on trial for study in
Woodbridge, New Jersey, during the summer of
1958. The units, installed for public use on a test
basis, gave the necessary opportunity to observe
use of the equipment by customers and operators.
The results of this study of the new features
were favorable. The coin telephones tried at
Woodbridge were the forerunners of an entirely
new coin set presently being designed for pro-
duction at the Indianapolis location of Bell Labo-
ratories. An appearance model of the new design,

The procedures for placing a call from a public
telephone are so well known that a requirement
for any new design is to leave them unchanged
so far as possible. For local calls, prepay service
would be continued, with dial tone withheld until
after the correct deposit is made.

A second requirement in the new design is more
flexible control of the basic rate—that is, the
amount the user must deposit to get dial tone
and dial his call without the assistance of an
operator. Convenience of adjusting local rates is
one advantage, of course, but another consequence
of flexible rate control is new possibilities for
automatic dialing of multi-unit calls. One appli-
cation, for example, is the placing of special coin
telephones along highways so that travelers can
directly dial a considerable distance into the next
large city.

For this purpose, a new “coin totalizer” device
was developed. This is an _ electromechanical
mechanism assembled on the lower section of the
coin chute. It can be adjusted in 5-cent steps for
any basic rate up to 25 cents merely by changing
the position of a cam, or, depending upon the
exact design, by using different cams. In the
drawing opposite a cam can be seen mounted on
the left part of a shaft included in the mechanism.

This illustration shows some of the details of
the “read-in” portion of the totalizer. Coin chan-
nels (right in drawing) guide the nickels, dimes
and quarters to strike a coin arm which protrudes
into an opening in the channel plates. The falling
coin causes rotation of the arm assembly about
the totalizer shaft. After a small initial rotation,
a ratchet mechanism is engaged, and the arm
assembly and totalizer shaft rotate together.
Then, after the coin leaves the arm, the arm as-
sembly returns to the start position, drawn by
the return spring. The totalizer shaft, however,
remains in the rotated position, held by the
“detent finger” seen beside the cam. The angle
through which the shaft advances is equivalent
to 10° for a nickel deposit, 20° for a dime and
50° for a quarter.

In this particular drawing, the cam is ar-
ranged to close a set of contacts after 20° of
rotation, or 10 cents. At this point, the problem
is to “count” the amount deposited by resetting
the totalizer shaft — that is, by rotating it back
to its original position. For this purpose, a self-
stepping relay (not shown in the drawing) is
brought into play. In stepping the totalizer shaft —
back to its start position, this relay operates once
for each 10° (5 cents) of rotation. The customer

A third requirement for the exploratory de-
velopment is to improve the coin signals. Instead
of using the traditional ‘‘gong and chime” type
sounds to identify nickels, dimes and quarters,
it was desirable to develop a system that would
be more adaptable to automatic methods. In the
new set, a transistor oscillator is switched on
briefly each time the stepping relay operates.

For example, suppose a user has deposited
10 cents (either two nickels or a dime). In
“erasing” this amount, the stepping relay oper-
ates twice; thus, it triggers the oscillator twice
and sends two “beeps” to the central office. There-
after, if an operator helps establish a longer-
distance call, she hears one “beep” for a nickel,
two for a dime, and five for a quarter. These
signals are electrically more discrete than the
older gongs and chimes, and therefore are more
easily incorporated into systems of direct dis-
tance dialing from coin telephones, where no
operator would be required.

The next drawing (right, below) is a block dia-
gram of the trial coin-telephone circuit. The rate
cam is designated T:, and T: is a totalizer contact
that short-circuits the telephone set whenever
the totalizer is storing information on coin de-

This arrangement demon-
strates how trial models of
new coin-telephone work. The
author, left, holds handset
that is comparable to opera-
tor’s headset, and L. A. Strom-
men holds new coin-signal net-
work in his right hand.

posits. If two nickels are used to start a local
call, T: and T: first advance to their 5-cent posi-
tions, and the coin-relay contact (bottom part of
the diagram) closes. At this point the central
office places battery and dial tone on the line, but
this tone cannot be heard in the receiver and the
number cannot be dialed. When the second nickel
is deposited, however, short circuits are removed
from the telephone set and from the stepping
relay. The rate relay (center of the diagram)
operates and the totalizer shaft is reset. The
rate relay then remains operated for the duration
of the call and permits the totalizer to be reset
immediately after any subsequent deposit of
coins. Each time the stepping relay operates, the
coin-signal network is energized to produce a
pulse of tone.

The coin-signal network is also shown in sche-
matic form on the next page. The transistor is
arranged in the common-emitter configuration
with a tuned collector circuit. Inductors Li, Le
and Ls are wound on a common core. When a
voltage is applied across the telephone line, the
oscillator is triggered, and feedback from L: to Lx
sustains oscillation. The output appears across
L. in the line. Components were mounted on an
etched-wire board and encased in epoxide resin.

Laboratory and Woodbridge tests were con-
ducted to find acceptable values for the coin
signals. A tone of 1016 cps was used, with each

pulse lasting about 50 milliseconds. The signals
were easily recognizable at pulse rates of 10 to
15 per second. Studies are continuing to deter-
mine the optimum signal.

A fourth major improvement was the develop-
ment of coin mechanisms that would reject a
high percentage of slugs and spurious coins. In
the exploratory unit, the upper section of the
coin chute contains such mechanisms, and has a
single opening for accepting nickels, dimes and
quarters.

All inserted pieces are tested to detect washers
and to determine weight, thickness, maximum
diameter, minimum diameter and ferromagnetic
properties. Another coin chute under development
will also test for eddy-current properties and will
give additional protection against fraud.

The new design introduces a clear-out feature
whereby the customer operates a bar to have
coins returned. In existing coin telephones, re-
jected pieces drop right through to the refund
receptacle, but in the new design, such pieces
are trapped in the chute until the customer
presses the bar. This new procedure permits bet-
ter rejection techniques, a saving of space, and
more effective clearout of slugs.

A fifth objective — improved coin disposal —
is now possible becaues of a new coin relay de-
veloped at the Indianapolis Laboratory (RECORD,
November, 1959). This relay provides a replace-
ment mechanism for existing coin telephones,
and preliminary models were used in the equip-
ment for the Woodbridge trial. It permits opera-
tion of a coin telephone at a greater distance

Block diagram of trial circuit. Contacts T: and
T: add amount deposited; stepping relay “‘counts”’
the amount by stepping totalizer shaft back to
its original position and sending out tone signals.

Schematic of coin signal network. Transistor
oscillator generates pulse (“5 cents”) whenever
voltage is applied to line, left, by coin deposit.

The functions of storing coins after they are
collected, and of tranferring them to the refund
opening, were also considered in the studies. A
larger and more secure cash compartment was
tested in the laboratory, along with a more
tamper-proof device covering the refund opening.
These were new, untried designs, however, and
have been reserved for future field testing.

Twelve exploratory models were used in the
Woodbridge trial. In brief, they indicated that
the new operating method, with a single slot
for all coins, was practicable. The need to operate
the “coin-return bar” to retrieve rejected coins
did not appear to be objectionable. Reaction to
the new coin tones was generally favorable, with
indications that the new type signals would be
increasingly satisfactory with larger percentages
of the station plant operating on that basis.
Subsequent to this trial, the Indianapolis group
began further development work aimed at re-
fining the components and designing an entirely
new enclosure. This phase of the work will con-
sider the security aspects of coin-set design re-
quired to minimize loss throygh theft, damage
and fraudulent operation.

For the more distant future, the Labora-
tories, in cooperation with the Customer Products
group of the American Telephone and Telegraph
Company, is studying many new ideas for fur-
ther improvements in public telephone service.
Among these are credit-card operation, change-
making devices, and more efficient and com-
fortable booth facilities. In this way, we intend
to continue the fine record of offering excellent
service at the “phone away from home.”

Printed-circ:tit designs place many extra
demands on traditional contact connectors.
A new multicontact connector promises to
speed designs requiring low insertion

and withdrawal forces, and to improve
greatly the connector as a circuit element.

In the design of military electronic systems,
it is desirable for reasons of manufacture, main-

into a number of subassemblies. During opera-
tion, these units are electrically connected by
wiring that is terminated in connectors. The use
of printed circuits and of automation tends to
accentuate this philosophy of design — thus in-
creasing the number of units and the number of
connectors required. Much consideration, there-
fore, needs to be given to the design of the con-
nector as a circuit element.

With earlier designs, connectors left much to
be desired. In particular, the electrical conti-
nuity between individual plug and jack elements
was often unsatisfactory. Also, the insulation
between elements was apt to be inadequate. More
recent designs reveal many improvements; but
a report by the Assistant Secretary of Defense,
issued in October 18, 1955, listed connectors as
the second most frequent source of trouble in a
total of 36,000 component failures.

One of the most prevalent design limitations
for connectors today is the high force required
to engage and to disengage the plug and jack
members. For example, a typical 30-circuit con-
nector often requires from fifty to sixty pounds
of force for engagement or disengagement. Such
forces applied manually — often under conditions
of human stress—may result in misalign-
ment and breakage of the connector or associ-

ated apparatus. On some jobs, connector break-
age is said to have run as high as 50 per cent
during system development testing. Connectors
are often disengaged by pulling on the connect-
ing wiring. This, of course, may produce even
more trouble. The connector shown was developed

Picture shows detail of a 40-contact chuck-type
connector. The forty collet-type chucks are loosely
held in the upper insulation block to permit self-
alignment of contacts. The two blocks of the plug
assembly are held together by screws that serve
as guide pins when plug and jack come together.

Graph shows average tightening torque, left, for
forty-contact connector vs. engagement forces.

by Laboratories’ engineers, and it overcomes
need for high insertion and withdrawal forces.

The jack member of this new connector has a
collet-type chuck (that is, a metal ring chuck)
which grips tightly the pin or plug member,
thereby establishing good electrical connection.
A collet adapter, operated by its own individual
collet spring in the plug member, accomplishes
the gripping action. These collet springs are
energized by tightening a bolt and nut common
to the complete connector. Within limits, this
arrangement of chuck, adapter, and spring can
be duplicated any number of times in the con-
nector. At present, only two connectors of this
type are in production. One of these has forty
contacts and the other has forty-eight.

If we look at the 40-contact connector, we see
that the jack assembly contains forty collet-type
chucks. These chucks are loosely held in the in-
sulating block, and the looseness allows for self-
alignment of the contacts. Forty mating pins
are molded into the plug assembly to permit pres-
sure sealing, so that when the unit is mounted,
no gases or dust can leak through the connector.
This is an important consideration for some
military applications. Collet adapters and their
springs are located in recesses in the outer block
of the plug assembly, and two blocks of the plug
assembly are held together by screws that also
serve as guide pins when the plug and jack as-
semblies are brought together. A wing bolt pro-
jects through the jack assembly and engages a
nut in the plug assembly when the two are
brought together.

This arrangement provides a connector for
which relatively low forces are required to turn

the wing bolt and bring the connector assemblies
together. Thus we have accomplished the major
objective of this connector design. Let us now
examine its other features.

Merely obtaining low insertion and with-
drawal forces is not enough. We must also have
reliability and low contact resistance. This con-
nector achieves both to a high degree.

The contacting surfaces of the chucks and the
pins are gold plated for protection against tar-
nish and other corrosion effects. When the sur-
faces mate, sliding action between the chuck
and pin prevents the lodging of dirt between
the contact parts. Each chuck member is divided
by saw slots to provide four independent jaws —
each of which presses against the pin. Thus, for
each contact there are four parallel paths. While
this principle is old in the art of electrical com-
munications, it is probably carried to a higher
degree of perfection in this connector than in
other connector designs.

This use of gold plating and parallel paths re-
duces contact resistance to a negligible value.
Measurement of the over-all resistance of each
chuck and pin connection of a 40-contact con-
nector after 0, 10, 100, 300, and 1000 insertions
showed the use factor to be negligible. The aver-
age over-all resistance was 0.0032 ohm for each
contact — of which the contact resistance is prob-
ably less than 5 per cent of this value.

Tests of insulation resistance and ability to
withstand shock, vibration and pressurization
more than met the requirements of the pertinent
military specification. Five of these connectors
were each engaged and disengaged 1000 times —
for a total of 200,000 circuit-continuity tests —
without a single failure. The probability is that
a system having up to 5000 chuck-type connectors
— with a maximum of 500 insertions each — will
have no circuit discontinuities in the connectors.
The graph illustrates their high performance.

High insulation resistance between contacts is
gained by using Orlon-filled diallyl phthalate
resin. The results obtained from temperature,
humidity and pressure tests satisfactorily met
all requirements.

Development of this connector was undertaken
to meet a specific need for which no suitable
connector existed. In the time that it has been
available it has proved satisfactory, and many
connectors of this type have been manufactured.

Memory is the warehouse of intelligence for
machines as well as for human beings.

This is one reason why Laboratories
engineers have devoted so much effort

to memory devices for the Electronic
Switching System. For temporary storage of
information they developed the barrier-grid
store—a high-speed memory that can store
up to as many as 16,000 bits of information.

To operate successfully, a telephone switching
system must be able to store large amounts of
information. This information may come from
many sources, varying from the digits each
customer dials, to the operating details specified
by the designers. Very little of this information,
however, can be used at the instant it becomes
available. For this reason, it must be stored in
some form such that it can be released to the
system when needed.

The length of time information is stored can
vary over extremely wide limits for different
systems or even different parts of the same sys-
tem. For example, the frequency of current
needed to ring a certain party line is information
used over and over again; it must be stored
indefinitely. On the other hand, dialed informa-
tion may be stored for only a few seconds. And
some information generated within the system
may even be stored for only a very small frac-
tion of a second.

This wide range of storage intervals means
systems designers must apply a wide range of
techniques and devices to perform the storage
function. But in general, the storage of infor-
mation in telephone switching systems can be

Consider a manual switching system wherein
an operator, orally given a telephone number,
mentally stores it while she seeks the proper
jack. Once she has made the connection, she no
longer needs the stored information. So she
immediately forgets it and re-uses her memory
for the next customer. This use of memory falls
into the class of “‘temporary” storage.

In quite a different class is the information
stored in the telephone directory. This infor-
mation is used over and over, and furthermore,
it seldom changes. Its memory form is classed
as “semi-permanent.” Because of their large
capacity requirements, most semi-permanent
memories are “non-human,” even in manual tele-
phone systems.

Automatic telephone switching systems have
entirely analogous storage needs. Therefore, the
experimental Electronic Switching System
(ESS) developed at Bell Laboratories (RECORD,
October, 1958) uses two new large memories —
one temporary and one semi-permanent. ESS is
based on the concept of minimization of equip-
ment needs through the use of high-speed elec-

tronics. So these memories must be faster-acting
than any previously developed.

The semi-permanent memory must have very
large capacity and very high reading, or infor-
mation obtaining, speeds. But, due to the infre-
quent changes in content, it may have relatively
slower writing, or information depositing, speeds.
This memory is called the flying-spot store (REc-
ORD, October, 1959). The temporary memory, al-
though large, has considerably smaller capacity,
but both reading and writing must be done at
high speed. This storage system is called the
barrier-grid store because its storage device is a
barrier-grid tube.

Basically, a barrier-grid tube consists of a beam-
forming electron gun and a non-conducting tar-
get the beam must strike. The gun is similar to
that found in a cathode ray tube. The target,
however, instead of being a phosphor-coated face
plate, is of special construction. It is built like a
sandwich, having: (1) a fine-mesh grid through
which the beam must pass (the barrier grid),
(2) a mica plate which the beam strikes, and (3)
a metal plate (the back plate).

Information is stored in the form of electric
charges on the mica plate. Imagine the mica to be
divided into discrete areas about the size of the
diameter of the electron beam. Each of these
areas may be charged to a positive or negative
potential, and since the mica is a non-conductor,
these potentials will remain essentially unchanged
as long as the beam is turned off. Thus each area
will store a single binary digit or “bit” of infor-
mation. Because the beam is small there may be
as many as 16,000 such areas and each tube can
thus store 16,000 bits of information.

The ESS requires the barrier-grid store to be
able to select any one of these areas and read or
change it in microseconds. This is done by chang-
ing the deflecting potentials while the beam is off
so that when turned on, it will strike only the de-
sired area. Because the sequence of areas selected
by ESS is completely arbitrary, this is known as
a “random access” store. One of the principal cir-
cuit problems associated with the store is that of
changing the deflecting voltages from one precise
value to another in less than a microsecond.

When the beam strikes a selected area, second-
ary electrons are emitted. These secondary elec-
trons may fall back to the area or may flow to the
barrier grid, depending on the relative potentials.
This means that if the mica area is more positive
than the barrier grid, secondary electrons will
return to the area. If the area is more negative
than the grid, the electrons will go to the grid.
Since the barrier-grid potential is held at a fixed

value, the mica potential must adjust itself until
the number of electrons leaving the area just bal-
ances the beam electrons arriving. This equilibri-
um potential of the mica is very nearly equal to
the potential of the barrier grid and, because of
the small area of the spots, is reached quite rapid-
ly — under a microsecond. This high sneed per-
mits a short cycle time in the barrier-grid store.

Equilibrium potential of an area represents a
bit of information, a binary 0, while a potential
20 volts more negative than this represents a
binary 1. The system uses the process of charg-
ing an area to an equilibrium potential both in
reading and writing.

For instance, to write a 0, the area is selected
and the beam turned on. After a microsecond, the
area is at equilibrium potential — it represents a
0. From observation of the current flowing to the
barrier grid during this interval, it may be deter-
mined whether the area was previously a 1 or a 0.
No pulse of charging current will be needed to
reach equilibrium if the area was already at equi-
librium, or was a 0.

Note that this process of reading is destructive
in the sense that by the time the original state of
the spot is determined it is at equilibrium poten-

B. A. Ackerman, left, and T. S. Greenwood with
model of barrier-grid store. Tube is located in tall
panel of upper-middle portion of cabinet. All cir-
cuitry is on removable chassis. Complete power
supply is in adjacent cabinet (behind author).

tial and thus always represents a 0. For this rea-
son, if a 1 is present and the system desires to
continue to store this 1, it must be rewritten. This
is done by first raising the backplate above its
normal potential and again turning the beam on.
The act of raising the backplate potential places
a positive charge on the area, but the beam re-
moves this charge in the process of charging the
area to equilibrium. Once at equilibrium the beam
is turned off, and then the backplate is restored
to normal potential. This final action places a
negative charge on the area and leaves it more
negative than the barrier grid—da stored 1.

The tube operates on a basic cycle of three
phases. During the first phase — DEFLECT —
the beam is off, while the voltages on the deflec-
ing plates are being changed from some previous
value to one that will direct the beam to the de-
sired spot. Immediately following this, the beam
is turned on and the stored information is read
— the READ phase. The final, or WRITE, phase
consists of writing the area, or spot, to its next
potential.

These three phases take approximately equal
times of 0.7 microsecond and, allowing time for
circuit recovery, the cycle may be repeated every
2.5 microseconds. The switching system initiates
each cycle by supplying an address in pulsed form,
plus a “start” pulse. The start pulse may appear
on any one of four leads, depending on what is to
be done during the WRITE phase. The four op-
tions are:

GENERATE).
(d) Write the opposite of the original infor-
mation (REVERSE).
The use of a barrier-grid tube in ESS thus re-
quires appropriate circuitry to generate the read-
ing and writing actions as well as to deflect the
beam to the desired spot. This assemblage of tube
and circuits is what constitutes the “store.”

The barrier-grid store has four major divisions
—the addressing or deflecting system, the tube
and its direct control circuits, a sequential control
section, and a readout section. A basic block dia-
gram of the store shown on page 473 indicates
the four circuits needed. The store receives each
deflecting address in the form of parallel digital
pulses. In other words, several signals arrive
simultaneously on several leads. The deflection
circuitry then must convert this digital input into
the two voltages necessary to deflect the beam
horizontally and vertically to the desired spot; it
must do this rapidly and accurately.

The accuracy required permits the beam to
deviate no more than a tenth of a spot diameter
from its desired location. For a large change in
spot position this means accuracies exceeding 0.1
per cent. Since the beam must be within this final
error limit before completion of the 0.7 micro-
second DEFLECT phase of the cycle, it must
move at very high speed.

The sequence-control section of the store gen-
erates the train of pulses needed to carry out the
cycle. It provides these pulses at the proper times
to integrate the operations of the addressing,
tube and readout sections. In this section the
operations are digital and may be carried out by
the repeated use of small functional circuits as is
done in other digital systems.

The basic parts of the readout section include
an amplifier to raise the output signals of the
tube to working level and detection circuits to
pulse the proper output cable. Although the sig-
nals from the store are low in amplitude initially,
they are relatively noise free and thus present no
basic reading problem.

The barrier-grid store together with the re-
quired voltage-setting circuits, is reasonably com-
pact. This entire store consists of one bay of
circuits and one bay of power-supply equipment.

As part of a telephone system, the barrier-grid
store can be primarily characterized by its 16,000-
bit capacity and its 2.5-microsecond random ac-
cess speed. There is, however, another very inter-
esting characteristic, typical of electrostatic
memories — the information-regeneration rate.

Although the information stored in a barrier-
grid tube is very stable when the beam is turned
off, in normal operation the low-level “spray” of
electrons within the tube causes a gradual de-
terioration of stored charges. This effect is most
severe adjacent to spots where the beam appears

Version of barrier-grid tube. Sixteen thousand
bits of temporary information are stored here.

Four major divisions of the barrier-grid store,
and the circuits that link them. Memory (the bar-
rier-grid store) receives its instructions from
both the deflection system and sequential control.

most often, but all spots must be periodically
rewritten for long-time storage. How often this
must be done is governed by a figure called the
Read-Around-Number, or RAN.

The RAN indicates the largest number of times
a given spot may be used before its immediate
neighbors must be rewritten. In the present bar-
rier-grid tubes, the RAN varies from spot to spot
from a value of 150 to several times this value.
To avoid interference between spots, the switch-
ing system is arranged to rewrite all the spots
within one second and never let the usage ratio
of adjacent spots exceed 150. Because writing is
so rapid, these extra rewriting operations use
less than 10 per cent of the system’s time.

Since a high order of reliability is essential to
telephone systems, the “error rate” of the barrier-
grid store is also an important factor. Specific
tests on present stores have indicated that the
error rate is less than one in ten billion. This is
a very low probability of error, but the high
speed of the store permits this many operations
in less than a day. Thus in actual systems two
stores would normally be checked against each
other. Under these conditions the probability of
simultaneous errors is practically non-existent.

A number of barrier-grid stores hav: been
built and operated for laboratory switching sys-
tems and for the laboratory trial of ESS. The
accumulated experience with these stores has in-
dicated that this form of memory can furnish
highly reliable, high-speed storage at economical
cost for future telephone switching systems.

Seven members of the Laboratories and three
others from the Bell System have been named
Fellows of the Institute of Radio Engineers. The
grade of Fellow, the I.R.E.’s highest membership
rank, is bestowed only by invitation on those who
have made outstanding contributions to radio
engineering or allied fields. I.R.E. Sections will
present the awards in areas where the recipients
live.

The new Fellows will be recognized at the an-
nual banquet to be held on March 23 at the
Waldorf-Astoria Hotel in New York City. Mem-
bers of the Laboratories and their citations are:

A. C. DICKIESON — “For contributions to wire
and radio communications.” He is Director of
Transmission Systems Development.

STEPHEN Dosa, Jr. — “For contributions in the
field of television signal transmission.” He is
Transmission Measurement Engineer in the
Transmission Systems Development Department.

P. G. Epwarps — “For contributions in the
field of telephone commrnications systems.” He is
Director of Development, Merrimack Valley
Laboratory.

W. H. C. Hiccins — “For contributions to mili-
tary electronics.” He is Director of Military Elec-
tronics Development.

F. L. Hopper — “For contributions in under-
water sound search and sound recording.” He is
Military Development Engineer at the Winston-
Salem, N. C., location of the Laboratories.

J. M. MANLEY — “For contributions to the
theory of modulators and parametric amplifiers.”
He is in the Guided Wave Research Department.

DOREN MITCHELL — “For contributions to long-
distance communications systems.” He is Special
Systems Engineer in the Special Systems Engi-
neering Department.

Among others named Fellows are J. P. Molnar
and J. H. Felker, formerly of Bell Laboratories,
and H. R. Huntley, Chief Engineer of the A.T.&T.
Company.

Mr. Molnar, a former Vice President of the
Laboratories and President of Sandia Corpora-
tion, was selected for his “contributions to gase-
ous and solid-state electron devices.” Mr. Felker,
former Director of Special Systems Engineering
and now Transmission Engineer at A.T.&T., was
selected for his “contributions to computer
technology.” Mr. Huntley was named for “con-
tributions to communications engineering.”

People in outside-plant and installation depart-
ments of the Operating Companies often require
temporary sources of light to facilitate their
work. Typical of the dark places that they may
encounter are underground cable areas and loca-
tions in certain equipment, such as the inside of
a terminal box. Also, installers are often con-
fronted with dark working areas in customer’s
homes. And, of course, many emergency situa-
tions arise during hours of darkness when quick
and dependable light sources are vitally important.

The many uses for temporary lighting have
resulted in standardizing several portable lighting
devices for the Bell System. A device may use
power from a building circuit or a portable gen-
erator, or may obtain power from batteries.
Examples of lights that use generated power are
the Portable Lamp and the B Floodlight. Types
which operate on batteries include such items as
the Dual-Battery Light, the work lamps and the
Head Lamp.

The portable lamp operates on 120 volts and
uses a 75-watt lampbulb fitted into a molded

flector assembly, and a 25-foot cord which termi-
nates in a three-wire grounded type of plug. The
handle is equipped with a “convenience outlet”
into which may be plugged a soldering iron or
an electric drill. The B Floodlight receives its
power from a 120-volt portable generator and
uses a 150-watt lampbulb. This source furnishes
general illumination around work areas and
serves as a warning to traffic near highway work-
ing areas. It is designed to be mounted on a
warning mast and is equipped with a friction
joint so that the direction of the light beam may
be adjusted.

The Dual-Battery Light is used in emergency
work on aerial lines. This light has an adjustable
feature which permits a beam of light to be di-
rected upward in a vertical are. A reflector on

The Head Lamp is an important source of light
when both hands must remain free. A diffusing
lens creates a broad beam of light for close work.

one end of the housing has an adjustment device
that permits the light beam to be focused, while
a reflector on the opposite end furnishes a pre-set
flood beam. A toggle switch on the case enables
the operator to select either beam. When the
unit is placed on the ground, and when the
focusing beam is directed upward to the work
area, the flood beam on the opposite end can be
used to illuminate the immediate area on the
ground. Two dry batteries, mounted in the case,
furnish the necessary power. Another battery-
powered light is the Electric Hand Lantern. This
is a general-purpose light, convenient to carry
when walking and searching. It furnishes a large
amount of illumination for its size and weight.

A portion of the cable-splicing operations car-
ried out by construction and maintenance men
takes place at night and also in dark locations
such as manholes. Illumination for these situa-
tions comes from “work lamps.” One of these
lamps uses a 6-volt storage battery, and consists
of an aluminum reflector, a lamp, a plastic lens,
a 25-foot cord, and a mounting bracket which can
be “telescoped.” The bracket is equipped with a
swivel to facilitate directing the light, a hook to

engage cable racks, and a clamp to secure the
unit to the cable-supporting strand.

A second type of work lamp uses two 45-volt
dry batteries. It consists of a 6-watt fluorescent
lamp enclosed in an aluminum reflector, a 25-foot
cord, a telescoping mounting bracket, and a steel
carrying case. The case has three compartments
— one serves as a housing for the batteries, an-
other for a spare lamp, and the third for space to
store the light fixture and the cord. The starting
switch, fuse, and current-limiting resistors are
mounted on a control panel inside the case. This
lamp operates for approximately 100 hours of
intermittent use on one set of batteries.

The Head Lamp is a useful device for directing
light on a work area while the hands remain free.
A typical application is in terminal work on tele-
phone poles. This lamp is held on the head by an
elastic band and may be adjusted up or down by
means of the bracket support that connects the
elastic band to the lamp housing. The housing is
equipped with a diffusing lens that projects a
broad beam of light on work at arm’s length. The
diffusing lens may be removed to throw a sharper
beam of light for a greater distance. The power
source consists of four “D” size batteries con-
tained in a case that fits in the workmen’s pocket
or clips to his belt. A four-foot, two-conductor
cord connects the case and the lamp housing.

Even the common flashlight is an important
way to provide temporary light for workmen

be fastened to a strand or a cable rack and whose
beam of light can be pointed in any direction.

of light upward or flood the area behind it, ac-
cording to which type of illumination is needed.

when they are moving about and performing vari-
ous tasks. About 100,000 flashlights are supplied
annually to the Bell System construction, installa-
tion and repair forces. Most of these are of the
“angle” type and are powered by two, 1'4-volt dry
batteries. In use, the light may be placed on end
on a flat surface or clipped to the belt if it is
desired to free both hands for work.

An important feature of the latest standard
flashlight is an improved slide type on-off switch.
This consists of a plastic switch body and a strip
assembly made of phosphor bronze that completes
the circuit when moved toward the head, or lens
end, of the light. Since this new switch construc-
tion is rugged, it is not likely to be damaged when
the flashlight is dropped or struck with other
tools.

Another recent development on the angle light
is a unique arrangement of lens and reflector.
The safety glass lens is held in place across the
face of the reflector with a rubber channel gasket
that fits over the edge of the lens and the lip of
the reflector. The lamp is secured at the rear of
the lens and reflector assembly by a plastic re-
tainer which may be unscrewed to replace the
lamp. This arrangement keeps the reflecting sur-
faces free from dirt and fingerprints.

Bigger Boron Crystals Produced
By Floating Zone Melting Method
And New ‘Pressed-Bar’ Technique

Because of its physical proper-
ties, boron does not ordinarily
lend itself to floating-zone refin-
ing, since it is not possible to
form the powder into a suitable
shape by pressure alone. The
pressed forms are so friable, so
easily crumbled, that they fall to
pieces as soon as they are re-
moved from their forming dies.

In one step of the new tech-
nique, boron powder is placed in
boiling boric-acid solution, and
the mixture boiled to dryness.
This coats the boron granules
with boric acid, permitting the
powder to be pressed into forms
that can be handled without
breaking.

The formed bars, or ‘compacts,’
are heated in two stages in a
vacuum for one hour, at tempera-
tures of 300 to 600 degrees C to
decompose the boric acid into
boron oxide. This compound forms
a liquid coating on the boron
particles. When the compact is
cooled, this liquid hardens, bond-
ing the powder into a strong bar.

the bar of boron powder is
mounted vertically. To melt a
narrow band, or zone, of the ma-
terial, a high-frequency induction
coil surrounds the bar. The molten
zone is moved down the rod by
raising the bar through the coil,
while the melted boron freezes or
crystallizes above the coil. Dur-
ing this operation, the ‘binder’ of
boron oxide sublimes — becomes a
gas directly — before the melting
point of boron (about 2000°C) is
reached. The method has pro-
duced crystals as large as 0.1
inch, many of which exist as twins.

Before mounting the compact,
the corners of the square bar are
ground off to minimize the ‘cage’
effect, in which the corners do not
melt. The resistivity of the boron
must be lowered so that it can
be heated and melted by high-
frequency induction. This is done
by heating a graphite cup adja-
cent to the top end of the bar.

The apparatus used in the float-
ing-zone refining is similar to that
used in the treatment of other ma-
terials, except that the rod of
boron is enclosed by two concen-
tric, transparent quartz tubes.
When the subliming boron ox-
ide covers the tubes enough to
restrict vision, the inner tube,
which is slotted, can be rotated
to give a clear field. This modi-
fication to the equipment has pre-
viously been used at the Labora-
tories in the floating-zone melting
of gallium arsenide by J. M.
Whelan and G. H. Wheatley, of
the Semiconductor Research De-
partment.

The U. S. Navy is erecting
what will be the largest radio
telescope in the world on a 1,500-
acre site in Sugar Grove, West
Virginia. The $79,000,000 struc-
ture is being designed by Grad,
Urbahn and Seelye, New York
architects-engineers. The Bureau
of Yards and Docks, acting for
the Naval Research Laboratory,
is the contracting agency. NRL
scientists formed the basic spec-
ifications and other criteria after
years of intensive research.

The concept of radio astronomy
originated in the work of Karl
Jansky in 1932. Working at the
Holmdel, New Jersey, location of
the Laboratories, he built what
was to become the first radio tele-
scope. Using a spiral antenna ar-
ray to study static disturbances,
he discovered that some of the
sources of radio noise are in the
center of the earth’s galaxy.

After scheduled completion in
1962, the Navy’s 20,000-ton facil-
ity, to be known officially as
“Naval Radio Research Station,”
will be the world’s most powerful
“ear to the universe.” It will en-
able NRL scientists to tune in on
radio signals emitted by astral
bodies as far as 38 billion light
years out in space — 19 times the
distance probed by the 200-inch
optical telescope at Mount Palo-
mar, California.

The instrument’s aluminum-
mesh reflector dish will have a
600-foot diameter, and an area ex-
ceeding seven acres. Rotation of
huge wheels supporting the dish
complex will elevate the reflector
in any direction between horizons.
Rotation of the entire structure
on rollers riding circular tracks
on the ground will turn the in-
strument to any point in azimuth.
Thus, the dish can be aimed at
any point in the sky above the
horizon. The telescope will be
electronically controlled from a
laboratory - operations building
near-by.

G. N. Thayer, formerly vice
president — operations of the
Ohio Bell Telephone Company,
was recently elected vice presi-
dent of the A.T.& T. Company, in
charge of the Marketing Depart-
ment.

Mr. Thayer joined the tech-
nical staff of Bell Laboratories
in 1930. He was appointed Direc-
tor of Transmission Development
in 1951, and was elected vice
president of the Laboratories in
1952, in charge of Military De-
velopment. Before he left the
Laboratories to go to A.T.&T.
as chief engineer in 1955, Mr.

Thayer was vice president in
charge of switching and trans-
mission development. Two years
later, in 1957, he went to Ohio Bell
as vice president — operations.

Mr. Thayer replaces J. W. Cook,
who was named vice president —
public relations of A.T.&T. Mr.
Cook in turn succeeds S. B.
Cousins in the public relations
post.

Mr. Cousins, formerly vice pres-
ident and general manager of Bell
Laboratories, was appointed vice
president — personnel, succeeding
H. Randolph Maddox, who will
retire at his own request effective

Effective December 1, J. E.
Dingman was elected vice presi-
dent and appointed Chief Engi-
neer of A.T.&T. He replaces H.
R. Huntley, who is retiring at
the end of this year.

Mr. Dingman began his Bell
System career with the Western
Electric Company in 1921 and

of Pennsylvania. He was vice
president and general manager
of Bell Laboratories from 1952
to 1956. Mr. Dingman has been
Director of Operations at Long
Lines for the past three years.

The cable ship Monarch left
San Juan, Puerto Rico, on Novem-
ber 4 for the Florida coast, where
it began laying the new tele-
phone cable between the United
States and Puerto Rico. This will
be the world’s deepest telephone
cable. The $17,000,000 project is
a joint undertaking of the Long
Lines Department of the A.T.&T.
Company and Radio Corporation

of Puerto Rico, a subsidiary of
International Telephone & Tele-
graph Corp.

Twin cables — one for each di-
rection of speech — will make up
the entire system. One end will be
at West Palm Beach, Florida.
From there, the cables will dip
into the intra-coastal waterway
and go underground across Palm
Beach. Then they will enter the
sea, run 20-30 miles apart, and
emerge 1,250 miles away on the
shores of San Juan. About 75
miles northwest of Puerto Rico,
the cables will drop to a depth of

five miles into the Puerto Rican
“trench,” the deepest point in the
Atlantic Ocean.

T. F. Gleichmann of the Trans-
mission Systems Development De-
partment is at West Palm Beach,
and R. M. Riley of the Outside
Plant Development Department is
aboard the Monarch.

The new twin cables, scheduled
for service early in 1960, will be
able to handle 48 simultaneous
conversations. This capacity will
help to meet the rapidly growing

A way to circumvent automati-
cally a certain type of distortion
of radio signals in turnpike pa-
trol cars has been devised at Bell
Laboratories recently. This dis-
tortion is encountered whenever
the vehicle is in a location on
the highway where the effective
areas of two transmitters overlap.

The phenomena, called “co-
channel” interference, results
when signals from two or more
stations, transmitting the same
intelligence on the same frequen-
cy, are received at similar in-
tensities. Equipment developed at
the Laboratories several years
ago precluded this distortion by
an arrangement that reversed the
directivity of a bi-directional re-
ceiver antenna located atop the
ear (RECORD, November, 1956).

This arrangement, however,
was mechanical — a switch had to
be operated to reverse the an-
tenna pattern. Since police of-
ficers often must patrol their
routes at high speeds and oper-
ate a variety of other equip-
ment, they are not always in a
position to operate this switch.
For this reason, the Laboratories
designed a system to do this auto-
matically. This development,
however, has not been carried to
the point where circuits and
equipment are available.

Basically, the switching is actu-
ated by two different tones, at a
low frequency, sent out from alter-
nate transmitters located along
the road. So long as a car’s re-
ceiver hears only one of these
tones, the antenna is not affected.
But as soon as the receiver notes
a second tone — when the car is
in a overlapping coverage area —
resonant and flip-flop circuits in
the system actuate a mechanism
that rotates the antenna pattern
180 degrees.

~The Monmouth County Histori-
cal Association has accepted the
gift of the historic Hendrick Hen-
drickson house in Holmdel, New
Jersey, through arrangements
made by the Bell Laboratories.
The structure, a unique example
of Colonial architecture dating
from about 1730, is situated on
the site of the new Holmdel labo-
ratory being built for Bell Labo-
ratories (REcorD, May, 1959).

The Association intends to re-
store the house to its original con-
dition on another site, and to fur-
nish the house in the manner in
which it might have appeared in
Colonial times. Upon completion
of the restoration, the home will
be open to the public. 3

A test model of the Army’s
Nike-Zeus Anti- Missile Missile
performed successfully in an ex-
perimental test firing at the
White Sands Missile Range on
October 14, Although the flight
terminated (during the coasting
phase) short of the planned tra-
jectory, it yielded the desired
technical data. The booster motor
and sustainer motor were fired
during the test. Both performed
successfully.

The Nike-Zeus booster, the mis-
sile’s first stage, is composed
of a single unit using a solid
propellent. It is the most powerful
rocket motor of its type ever
known to be fired, developing more
than 400,000 pounds of thrust at
launch. The engine was devised by
the Thiokol Chemical Corporation,
Redstone Arsenal, Alabama.

Grand Central Rocket Com-
pany, Redlands, California, devel-
oped the sustainer engine which
will make up the second stage of
the Nike-Zeus.

Purpose of the ‘est flight was
to obtain information on flight
and propulsion characteristics of
the missile. Nike-Zeus is being
developed by Bell Laboratories
for the U. S. Army Ordnance
Corps to defend the nation against
intercontinental ballistic missiles.
The Western Electric Company is
the prime contractor.

The experimental test firing
was conducted by Bell Labora-
tories and Douglas Aircraft Com-
pany personnel stationed at the
missile range.

The November 1959 BELL SYSTEM
TECHNICAL JOURNAL contains the
following articles:

An Experimental Transistor-
ized Artificial Larynx, by H. L.
Barney, F E. Haworth and H. K.
Dunn.

Gyromagnetic Modes in Wave-
guide Partially Loaded with Fer-
rite, by H. Seidel and R. C.
Fletcher.

Error-Correcting Codes — A
Linear Programming Approach,
by E. J. McCluskey, Jr.

The Analysis of Valve-Con-
trolled Hydraulic Servomecha-
nisms, by R. G. Rausch.

Design Considerations for High-
Frequency Transistor Amplifiers,
by D. E. Thomas.

Effects of Tamping and Pave-
ment Breaking on Round Conduit,
by G. F. Weissmann and D. M.
Mitchel.

A.S.A./A.S.Q.C. CONFERENCE
ON MATHEMATICS AND STA-
TISTICS FOR RELIABILITY PROB-
LEMS, New York, N. Y.

Gupta, S.S., Order Statistics from
Gamma Distribution and Their
Applications to Life-Test and
Reliability Problems.

Levenbach, G. J., Exploring the
Basic Mechanism of a New De-
vice—A Non-Linear Estimation
Problem.

Bozorth, R. M., Ferromagnetism
of Some New Compounds: Su-
perconductors and Substituted
Garnets.

David, E. E., Jr., Guttman, N.,
and van Bergeijk, W. A., Bin-
aural Interaction of Impulsive
Stimuli.

David, E. E., Jr., Mathews, M. V.
and Miller, J., Monaural Phase
Effects in Speech Perception.

David, E. E., Jr., Mathews, M. V.
and Vyssotsky, V. A., Recogni-
tion of Voicing, Voice Pitch and
Formant Frequencies with a
Digital Computer.

Flanagan, J. L., A Resonance-
Vocoder and Baseband System
for Speech Transmission.

Mason, W. P., Phonon Viscosity
and Its Effect on Acoustic Wave
Attentuation and Dislocation
Motions.

Mathews, M. V., David, E. E., Jr.,
and McDonald, H. S., Digital
Computer Simulation as a Tool
in Speech Research.

Schroeder, M. R., Improvement of
Acoustic Feedback Stability in
Public Address Systems.

Schroeder, M. R., A New Auto-
matic Method for Measuring the
Reverberation Time and the
State of Diffusion of a Room.

Schroeder, M. R., Recent Progress
in Speech Coding at Bell Tele-
phone Laboratories.

van Bergeijk, W. A. and David,
E. E., Jr., Simulation of the Ex-
ternal Spiral Innervation of the
Cochlea.

Baker, A. N., Stored Charge Anal-
ysis of Transistor Operation,
Graduate Seminar in Electrical
Engineering, Polytechnic Insti-
tute of Brooklyn, Brooklyn,
N. Y.

Bozorth, R. M., Magnetic Proper-
ties of Ferromagnetic Super-
conductors, Gordon Research
Conference, New Hampton,
N. H.

Brattain, W. H., Development of
Concepts in the Understanding
of Semiconductors, Science Fac-
ulty Colloquia, Rensselaer Poly-
technic Institute, Troy, N. Y.

Carbrey, R. L., Video Transmis-
sion Over Telephone Cable by
Pulse Code Modulation, Fifth
National Communications Sym-
posium, Utica, N. Y.

Danylchuk, I., Magnetic Amplifier
Binary-to-Analog Conversion,
Special Technical Conference
on Non-linear Magnetics and
Magnetic Amplifying, Washing-
ton, D. C.

David, E. E., Jr., Digital Simula-
tion in Perceptual Research,
National Electronics Confer-
ence, Chicago, III.

David, E. E., Jr., Some Problems
in Speech Recognition, Seminar
on Speech Compression and
Processing, Air Force Cam-
bridge Research Center, Cam-
bridge, Mass.

Deutsch, M., Experiments on So-
cial Perception, Psychology
Club of Brooklyn College, N. Y.

Ellis, W. C., Mechanisms of
Growth and Properties of
Whisker Crystals, Seminar De-
partment of Metallurgy and
Material Science, Northwestern
University, Evanston, Ill.

Ferrell, E. B., Fundamental Con-
cepts of Statistical Analysis,
Utica-Rome Chapter, A.S.Q.C.,
Utica, N. Y.

Fuller, C. S., Chemical Equilibria
and Reactions in Semiconduc-
tors, International Union of
Pure and Applied Chemistry,
Munich, Germany.

Germer, L. H., Diffraction of Low
Energy Electrons, Cornell Uni-
versity, Ithaca, N. Y.

Geusic, J, E., Evaluation of Maser
Action in Ruby in the Frequency
Range 500-9000 me, Seventeenth
Annual Conference on Electron
Tube Research, Mexico City,
Mexico.

Geusic, J. E., The Paramagnetic
Resonance Spectrum of Cobalt
Doped A,O; at 1.6°K, Meeting
of the American Physical So-
ciety, Washington, D. C.

Grahan, R. E., A Noise-Stripping
Process for Picture Signals,
Eighty-Sixth Convention of the
Society of Motion Picture and
Television Engineers, N. Y. C.

Greiner, E. S., The Floating Zone
Melting of Boron and the Prop-
erties of Boron and Its Alloys,
Conference on Boron, United
States Army Signal Research
and Development Laboratory,
Asbury Park, N. J.

Guldner, W. G., Applications of
Vacuum Techniques to Analyti-
cal Problems, Western Electric
Training Course, Allentown, Pa.

Guldner, W. G., and Beach, A. L.,
The Effect of Evaporated Films
on the Recovery of Gases during
Vacuum Fusion Analyses, Ana-
lytical Chemistry Symposium
on Gases in Metals, Pitt., Pa.

Hagner, D. R., Ballistic Missile
Guidance, Joint Meeting of
LR.E., A.L.E.E. and A.S.M.E.,
Panama City, Fla.

Hamming, R. W., Current and Fu-
ture Trends in Digital Comput-
ing, Long Island Chapter A.C.M.,
Garden City, N. Y.

Hamming, R. W., Summer Course
on Frontier Research in Digital
Computers, University of North
Carolina, Chapel Hill, N. C.

Hopfield, J. J., Exciton Fine Struc-
ture in ZnO and CdS, General
Electric Laboratory, Schenec-
tady, N. Y.

Hopfeld, J. J., Observable Prop-
erties of Longitudinal Exciton,
IBM Research Laboratory,
Poughkeepsie, N. Y.

Jaccarino, V., Nuclear Magnetic
Resonance in Magnetic Crystals,
National Institute of Health,
Bethesda, Md.

Landau, H. J. and Pollak, H. O.,
Energy Relations between Func-
tions and Their Fourier Trans-
forms, American Mathematical
Society Meeting, Salt Lake City,
Utah.

Lee, C. A., The Preparation and
Electrical Properties of Alloyed
P-N Junctions of InSb, Semi-
conductor Symposium of the
Electrochemical Society, Colum-
bus, O.

Mason, W. P. and Thurston, P. N.,
A Compact Electromechanical
Bandpass Filter for Frequen-
cies Below 20 KC, National Ul-
trasonic Symposium, Stanford
University, Stanford, Calif.

Massey, R. P., Transistor-Core
Converter for High Input Volt-
ages, National Electronics Con-
ference, Chicago, IIl.

Mendizza, A., Plated Coatings for
Electrical Contacts, Joint Ses-
sion of Newark-New York
Branches of American Electro-
piaters Society, N. Y. C.

Miller, J. A., Post-Graduate Train-
ing for the Engineer in Indus-
try, Eastern North Carolina
Sub-section of A.S.M.E., Raleigh,
N. C.

Miller, L. E., Uniformity of Junc-
tions in Diffused Silicon Devices,
A.I.M.E. Semiconductors Ses-
sion, Boston, Mass.

Morrison, J., The Behavior of
Titanium in a High Vacuum,
American Vacuum Society Sym-
posium, Philadelphia, Pa.

Och, H. G., Functions of Manage-
ment, Ordnance Weapons Com-
mand Headquarters, Rock Is-
land, Ill.

Pollak, H. O., The Aims and Phi-
losophy of the Ninth-Grade
Committee of the School Mathe-
matics Study Group, Mathemat-
ics Teachers Meeting, Chicago,
Til.

Pondy, P. R. and Helmke, G. E.,
Measuring and Controlling Dust,
A.S.T.M. Symposium on Clean-
ing of Electronic Device Compo-
nents and Materials, Phila., Pa.

Prescott, R. E., Some Design As-
pects of Molded Circuits, Sym-
posium on Printed Circuits, Bell
Laboratories, Murray Hill, N. J.

Prim, R. C., Some Minimax Prob-
lems for Labeled Graphs, Amer-
ican Mathematical Society, Salt
Lake City, Utah.

Purvis, M. B. and Staehler, R. E.,
The Role of Photographic Stor-
age in Electronic Telephone
Switching Systems, Society of
Photographic Scientists and En-
gineers, N. Y. C.

Ruppel, A. E., The Dew Line
Story, Hempstead Bay Power
Squadrons, Hempstead, N. Y.

Schroeder, M. R., New Results
Concerning Monaural Phase
Sensitivity, Pavlov Institute of
the U.S.S.R. Academy of Sci-
ences, Leningrad, Russia.

Schroeder, M. R., On the Steady
State Sound Transmission in
Rooms, Acoustic Institute of the
U.S.S.R. Academy of Sciences,
Moscow, Russia.

Schroeder, M. R., Vocoders for
Military Use, Air Force Re-
search Center, Bedford, Mass.

Schulz-DuBois, E. O., The Travel-
ing Wave Maser, University of
Michigan, Ann Arbor, Mich.

Scovil, H. E. D., Lecture Series on
Masers, White Sands Missile
Proving Ground, Las Cruces,
N. M.

in Electronics, Bell Laborato-
ries-Western Electric Printed
Wiring Symposium, Summit,
N. J.

in Quality Control, Eleventh
Rutgers Conference on Quality
Conirol and Statistics in Indus-
try, New Brunswick, N. J.
Thurston, R. N., see Mason, W. P.
Walters, A. E., Minority Carrier
Lifetime in Neutron-Bombarded
Germanium, Second Conference

on Nuclear Radiation Effects on
Semiconductor Devices, Mate-
rials and Circuits, N. Y. C.
White, A. H., Physics in the Com-
munication Field, Second An-
nual Corporate Associates Meet-
ing, American Institute of
Physics, Harriman, N. Y.

Following is a list of the authors, titles, and places of publica-
tion of recent papers published by members of the Laboratories.

Allison, H. W. and Samelson, H.,
Diffusion of Aluminum, Mag-
nesium, Silicon and Zirconium
in Nickel, J. Appl. Phys., 30, pp.
1419-1424, Sept., 1959.

Amron, I. and Koontz, D. E., An
Ultrasonic System for Elimi-
nating Physical Contaminants
from Electron Devices, Ultra-
sonic News, III, pp. 8-19, Sept.,
1959.

Anderson, P. W., The Knight
Shift in Superconductors, Phys.
Rev. Letters, 3, pp. 325-326, Oct.
1, 1959.

Anderson, P, W., A New Approach
to the Theory of Superexchange
Interactions, Phys, Rev., 115,
pp. 2-13, July 1, 1959.

Batterman, B. W., X-Ray Meas-
urement of the Atomic Scatter-
ing Factor of Iron, Phys. Rev.,
115, pp. 81-86, July 1, 1959.

Beach, A. L. and Guldner, W. G.,
The Effect of Evaporated Films
on the Recovery of Gases Dur-
ing Vacuum Fusion Analyses,
Anal. Chem., 31, pp. 1722-1726,

Birdsall, H. A., Insulating Films,
Chapter IX, 1958 Digest of Lit-
erature on Dielectrics, 22, pp.
239-251, Oct., 1959.

Budenstein, P. P., Burrus, C. A.
and Ohl, R. S., Improved Diode
for the Harmonic Generation of
Millimeter and Submillimeter
Waves, Rev. Sci. Instr., 30, pp.
765-774, Sept., 1959.

Clogston, A. M., Schawlow, A. L.
and Wood, D. L., Electronic
Spectra of Exchange Coupled

Clogston, A. M., LeCraw, R. C.
and Spencer, E. G., Low Tem-
perature Line Width Maximum
in Yttrium Iron Garnet, Phys.
Rev. Letters 3, pp. 32-33, July
1, 1959.

Danylchuk, I. and Katz, D., Mag-
netic Amplifier Binary-to-Ana-
log Conversion. Proc., Special
Tech. Conf. on Non-linear Mag-
netics and Magnetic Amplify-
ing, pp. 306-312, Sept., 1959.

DeLoach, B. C. and Sharpless, W.
M., An X-Band Parametric Am-
plifier, Proc. I.R.E., 47, pp.
1664-1665, Sept., 1959.

Douglass, D. C. and McCall, D. W.,
Note on the Melt Configuration
of Polyethylene, J. Chem. Phys.,
31, pp. 860-861, Sept., 1959.

Flaschen, S. S., Northover, W. R.
and Pearson, A. D., Low-Meit-
ing Inorganic Glasses with High
Melt Fluidities Below 400°C, J.
Am. Cer. Soc., 42, p. 450, Sept.,
1959.

Geballe, T. H., Radiation Effects
in Semiconductors: Thermal
Conductivity and Thermoelec-
tric Power, J. Appl. Phys., 30,
pp. 1153-1157, Aug., 1959.

Geller, S. and Gilleo, M. A., The
Interaction of Magnetic Ions
in Gd; Mn: Ge: GaOn and Re-
lated Garnets, J. Phys. & Chem.
of Solids, 10, pp. 187-190, 1959.

Geusic, J. E., DeGrasse, R. W.,
Schulz-DuBois, E. O. and Sco-
vil, H. E. D., Three Level Spin
Refrigeration and Maser Action
at 1500 me/sec., J. Appl. Phys.,
30, pp. 1113-1114, July, 1959.

Hardy, F., Development of Special
Lubricants and _ Lubrication
Practices for Small Apparatus,
J. Am. Soc. Lubrication Engi-
neers, 15, pp. 328-332, Aug.,
1959.

Leenov, D. and Uhlir, A. Jr., Gen-
eration of Harmonics and Sub-
harmonics at Microwave Fre-
quencies with P-N Junction
Diodes, Proc. I.R.E., 47, pp.
1724-1729, Oct., 1959.

Li, Tingye, A Study of Spherical
Reflectors as Wide-Angle Scan-
ning Antennas, I1.R.E. Trans.,
Prof. Gp. Antennas and Propa-
gation, 7, pp. 223-226, July,
1959.

Reed, E. D., The Variable-Capaci-
tance, Parametric Amplifier,
I.R.E. Trans. Prof. Gp. Electron
Devices, 6, pp. 216-224, April,
1959,

Roberts, S. W., Control Chart
Tests Based on Geometric Mov-
ing Ranges, Technometrics, 1,
pp. 239-250, Aug., 1959.

Schroeder, M. R., Methoden zur
Messung der Diffusitat in Hall-
raumen, Acoustica, 9, pp. 256-
264, July, 1959.

R. B., The Structure of the
Thermochromic Form of Bian-
throne, J. Am. Chem, Soc., 81,
p. 5005, Sept, 20. 1959.

Wasserman, E., The Electron Spin
Resonance of the Thermochro-
mic Form of Bianthrone, J. Am.
Chem. Soc., 81, pp. 5006-5007,
Sept. 20, 1959.

Fleckenstein, W. O., Kretzmer, E.
R. and Michel, W. S.— Fac-
simile Communication System
—2,909,601,

Mason, W. P.—Apparatus for
Eliminating Mechanical Vibra-
tions in Aerial Cables — 2,907,-
811.

Thomas, L. C. — Transistor Com-
parator Circuit for Analog to
Digital Code Conversion — 2,-
909,676,

V. M. Cousins joined Bell Labo-
ratories in 1925, with a group
designing sound systems. He was
a member of the Special Products
Development Department and its
successors up to World War II,
and since then has worked on
military projects. He participated
in the design of circuits for am-
plifiers and associated equipment
for sound motion pictures and
public address systems, and
worked on Naval sonar and com-
munications equipment between
1925 and 1940. Then he trans-
ferred to a group developing the
research and development model
of the M9 Anti-Aircraft Fire Con-
trol System. He was concerned
with the development of comput-
ers for this and similar fire-con-
trol systems until the end of the
war. In 1945 he took charge of a
group responsible for the circuit
design of the Nike research and
development guidance computer.
Since 1953, Mr. Cousins has
headed a group which designs and
operates the Nike System Tester,
the subject of his article. A na-
tive of North Dakota, he received
B.S.E.E. degree from the Univer-
sity of Minnesota in 1925.

Newton Monk, born in Stough-
ton, Mass., received the A.B. de-
gree from Harvard College in
1920 and the B.S. degree from
the Harvard Engineering School

in 1922. He then joined the D.&R.
Department of the A.T.&T. Co.
where he worked on _interfer-
enve prevention and carrier de-
velopment. This later activity
was continued when he transfer-
red to the Laboratories in 1934,
and he was associated with early
applications of carrier to rail-
road and other private communi-
cation systems. During World
War II he was engaged in the
development of military com-
munications. Since the war he
has been in charge of a group
developing radio systems for rail-
roads and airplanes and, more
recently, personal signaling sys-
tems. He is a member of A.I.E.E.,

a senior member of I.R.E., and
served for two years as chairman
of the Professional Group on
Vehicular Communications of the
latter organization. Mr. Monk
is the author of the article on
personal signaling in this issue.

Evan E. Thomas was born near
Swansea, Wales, and attended the
University of Wales and British
Naval schools. After a period of
navy teaching, he came to the
United States in 1928, and joined
Bell Laboratories almost imme-
diately as a member of the then
metallurgical group of the Chem-
ical Department. Here, he became
engaged in gas-metal studies and

then in lead-alloy studies for cable
sheathing. Since 1931, he has
specialized in optical microscopy,
the subject of his article in this
issue. His work has covered a
wide range of metallic materials
and semiconductors. Mr. Thomas
is a member of Sigma Pi Sigma
and the American Society for
Metals. He received the M.S. de-
gree from New York University
in 1939.

the Air Force he served with the
98th Bomb Group in Italy and
subsequently received a B.S. in
M.E. from Rutgers University in
1947 and his M.S. in mechanical
engineering from Newark College
of Engineering in 1951. He joined
the Laboratories in 1947 and was
first engaged in the development
of the ringer and dial for the 500-
type telephone. He was appointed
a superviscr in charge of devel-
opment of a new coin telephone
in 1955, and is presently in charge
of a group engaged in exploratory
development of station apparatus
including public telephones, sig-
naling apparatus and station con-
nectors.

Engineering from Northeastern
University in 1951 and his M.S.
in Electrical Engineering from
the Massachusetts Institute of
Technology in 1953. While at
M.I.T. he worked on storage de-
vices for the Whirlwind computer,
a forerunner of the SAGE com-
puter. He joined the Laboratories
in 1958 and has since been asso-
ciated with the development of
memory devices for the Electronic
Switching System. Until this year
he has worked on the barrier-grid
store, the transient memory for
the system. He is now in charge
of a group developing its semi-
permanent memory — the flying-
spot store.

is an enduring work of excellence a
a It can be a painting, a symphon
a an be a work of science or engine.

Nd author.
yora Novel,
ering, too.
Potential classics in science and engineering
being written today. Time alone can tell which
are will endure. Surely, they will be found
of sagt books which are today accepted as
authorities in their fields.
e

; s have written many such authoritative
They encompass the fields of information
books. semiconductor physics and chemistry, net.
theory, ry, statistical quality control, sound and
wave tubes and dislocations
acoustics,

in crystals.
More than +0 of these technical works have
} ublished since 1926. All have evolved from
been p atories’ continuing efforts to improve
me — telephone service. They reflect the
your ae the scientific thinking which helps
Se» this service the world’s best.

Bell Laboratories Record  1959-12: Vol 37 Iss 12