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Second prinfing Illustrated,! 




Because synthetic rubber and gaso- 
line, the sulfa drugs, chemical fabrics, 
new speeds and altitudes in the air, 
new sources of power are headline 
news, of increasingly vital interest in 
the daily lives of Americans. 

WORLD shows, in clear non-technical 
language, what is going on in the re- 
search laboratories of America today 
what the new processes, discov- 
eries and developments will mean 
for all of us, in the winning of the 
war and in the peace to follow. 


Glass that will bend, that can be spun 
into fabric; plastics used in a thousand 
household articles; synthetic silks that 
will not run or rot; synthetic wools that 
moths cannot eat; three-dimensional 
movies; helicopter "taxis"; light that 
flows round corners; power from the 
sun's rays or from uranium; all these 
are realities or possibilities that will 
play their part in tomorrow's world, 
that will create new industries and 
new jobs. 

CP/eose turn to back Hap"} 

From the collection of the 

1 f d 

7 n 
* m 

o Prelinger 
v Jjibrary 

t P 

San Francisco, California 





(see page 42) 





Author of " Stars and Telescopes/ etc. 



All Rights Reserved 

No part of this book may be reproduced in any form 

without permission in writing from the publisher, 

except by a reviewer who may quote brief 

passages in a review to be printed in a 

magazine or newspaper 



A cknowledgments 

It is, I think, obvious that the preparation of a book covering as 
many branches of science as this requires information obtained from 
many sources. Technical books, papers in scientific journals, official 
releases from industries and from the meetings of various societies, 
private correspondence to all these the author went for material. 

Particularly do I wish to express my indebtedness to Laurence A. 
Hawkins, executive engineer of the General Electric Research Labo- 
ratory, for his help and suggestions, and to Joseph L. Smith and 
Helena A. Stalnacke, of Ives Washburn, Inc., for their skillful atten- 
tion to the many technical details involved in bringing this book to 
completion. And among others who helped in many ways for ex- 
ample, by furnishing data or by checking the text I desire to thank 
the following: C. R. Addinall, Merck and Co.; Frank Benford, G. E. 
Research Laboratory; J. R. Brown, Jr., Esso Laboratories; Harold 
Burris-Meyer, Stevens Institute of Technology; Ernest E. Charlton, 
G. E. Research Laboratory; N. R. Chillingworth, Mine Safety Ap- 
pliances Co.; Watson Davis, Science Service, Inc.; Saul Dushman, 
G. E. Research Laboratory; Gustav Egloff, Universal Oil Products 
Co.; Raymond M. Fuoss, G. E. Research Laboratory; James T. Grady, 
American Chemical Society and Columbia University; William A. 
Hamor, Mellon Institute; Hoyt C. Hottel, Massachusetts Institute 
of Technology; Ernest L. Little, National Farm Chemurgic Council; 
Vincent Lyons, Celanese Corporation; Don Masson, Bakelite Corpo- 
ration; John Mills, Bell Telephone Laboratories; William H. Milton, 
Jr., G. E. Plastics Department; Frank J. Norton, G. E. Research 
Laboratory; G. Edward Pendray, Westinghouse Electric and Manu- 
facturing Co.; Walter A. R. Pertuch, The Franklin Institute; Neil 
B. Reynolds, Central Electric Co.; H. M. Richardson, G. E. Plastics 
Dept.; John J. Rowlands, Massachusetts Institute of Technology; 
M. L. Sandell, Eastman Kodak Co.; Waldo L. Semon, Hycar Chemical 
Co.; Igor I. Sikorsky, Vought-Sikorsky Aircraft; Burwell B. Smith, 
S. Morgan Smith Co.; Steven M. Spencer, E. I. du Pont de Nemours 
and Co.; Mary Stevenson, Columbia University; J. W. Stillman, E. I. 
du Pont de Nemours and Co.; Perry R. Stout, Massachusetts Institute 
of Technology; Herbert H. Uhlig, G. E. Research Laboratory; B. L. 



Vosburgh, Schenectady, N. Y.; Robert R. Williams, Bell Telephone 
Laboratories; and Vladimir K. Zworykin, RCA Laboratories. 

I also wish to express my appreciation to the following firms who 
furnished illustrative material: Bettmann Archive, photograph 2; W. 
Atlee Burpee Co., photograph 32; Celanese Corporation of America, 
jacket illustration of Celanese; Celluloid Corporation, jacket illus- 
tration of Lumarith; Dow Chemical Company, jacket illustration of 
Dowmetal; E. I. du Pont de Nemours & Company, photograph 4 and 
jacket illustrations of rayon thread, Exton, Lucite and Nylon; East- 
man Kodak Co., photograph 28; General Electric Co., photographs 
8, 9, 11, 13, 14, 15, 17, 18, 20, 21, 22, 23, 24, 25, 26, 27, 29 and 35; 
Hanovia Chemical and Manufacturing Co., photograph 7; J. B. 
Lippincott Company, diagram on page 99, from their publication, 
"Nutrition in Health and Disease," by Cooper, Barber, Mitchell; 
Merck and Co., photograph 2; Mine Safety Appliances Co., photo- 
graph 3; Modern Plastics Magazine, jacket illustration of Texolite; 
Monsanto Chemical Company, photograph 4; Owens-Corning 
Fiberglas Corporation, photograph 10 and jacket illustration of 
Exterminator Ray; R.C.A. Research Laboratories, photograph 19; 
Shell Oil Company, Inc., photograph 1, copyright by Shell Oil Co., 
Inc.; S. Morgan Smith Co., photograph 34; Standard Oil Company of 
New Jersey, photographs 5 and 6; Tennessee Eastman Corporation, 
jacket illustration of Tenite; University of California, photographs 
31 and 33; Vought-Sikorsky Aircraft, photograph 12; Westinghouse 
Electric and Manufacturing Co., photographs 16, 30, and jacket 
illustration of Atom Smasher. 


I. New Frontiers 1 

II. Explosives in Peace and War 12 

III. Fuel for Tomorrow 24 

IV. The Realm of Plastics 35 
V. Chemical Clothes 48 

VI. Rubber from Tree and Test Tube 59 

VII. Chemistry and the Farmer 70 

VIII. Chemicals for Cures 85 

IX. Vitamins 92 

X. New Metals 111 

XL Mining the Ocean 129 

XII. The Magic of Glass 136 

XIII. Higher, Faster, Farther ... 155 

XIV. The Age of Electrons 168 
XV. Radio Today and Tomorrow 187 

XVI. Light and Light Sources 210 

XVII. Pictures of the Future 226 

XVIII. New Sounds in the Theater 244 

XIX. Into the Atom 255 

XX. New Sources of Power 267 

Appendix: Rubber and Its Relatives 285 

Index 289 


1. Combat flyer s plastic "greenhouse" . . . shatter- 

proof, light in weight, permanently clear Frontispiece 

Facing page 

2. From the work of ancient alchemists comes 

modern chemistry 16 

3. Cable splicer powered by explosive, in use by a 

lineman 17 

4. Plastics come in many forms and colors some 

beautifully transparent 32 

5. A stage in processing butyl rubber from petro- 

leum-refinery gases 33 

6. Oxygen soon cracks a tube of natural rubber, but . 

one of butyl rubber is not affected 33 

Between pages 112-113 

7. Typical installation of Vitamin D milk irradiators 

8. Magnets to hold dentures in place 

9. Tiny magnet supports girl 

10. Glass is made into a fiber from which are spun 

beautiful fabrics 

11. Glass is made non-reflecting in this great sphere 

12. Like a humming bird, Igor Sikorsky hovers in his 


13. To make planes fly higher turbosupercharger 

parts / 

14. 1,400,000-volt X-ray machine 



15. With million-volt X-rays men look through steel 


16. High-speed radiograph of a football being kicked 

Between pages 192-193 

17. Studying plastic replicas of snowflakes showed 

how to view metals in electron microscope 

18. Model of a crystal as revealed by the electron 


19. The electron microscope extends mans range of 


20. Carbon steel magnified 2000 times with light 

microscope and 28,000 times with electron 

21. How FM reduces static to the vanishing point 

22. Television Studio WRGB 

23. Ice melts in a jar of water 

24. High-intensity mercury lamp tests flaws in glass 

25. Fluorescence makes airplane instruments visible 

at night 

Between pages 256-257 

26. Power from sunlight 

27. Chemical light 

28. Stroboscope photograph of a falling glass of water 

29. Huge test tube for separating isotopes 

30. Inside a Van de Graaff generator 

31. Cyclotron under construction 

32. New variety of calendula produced by X-rays 

33. Radiophosphorus as tracer element in tomato 

34. Power from wind on Grandpa's Knob 

35. 20,000,000-volt electron whirlpool 




I. New Frontiers 

Today's most promising frontiers are those of science those 
which are being explored by research workers in laboratories 
both great and small. They have largely replaced the geographi- 
cal frontiers of the past. And these new frontiers have a great 
advantage over the older ones. After all, space on the earth's land 
masses is limited, but the scope of exploration in science is infi- 
nite. Whenever science, in the past, has seemed to reach a dead 
end, a new road has opened, generally far broader than that left 
behind. There is every reason to think that this will continue 
indefinitely that we shall never reach a state where knowledge 
will be complete. 

Although its roots extend back into past centuries, present- 
day research is mainly a development of the last fifty years. Be- 
fore that time there were isolated workers, or at most small 
groups, mainly in college and university laboratories. They made 
great and important contributions as, for example, when Joseph 
Henry in the United States and Michael Faraday in England 
independently discovered the principles upon which all genera- 
tion of electricity now depends. Until about the beginning of 
the twentieth century, however, there was little or no effort to 
co-ordinate industry with research to make the results of the 
laboratory available for some practical use. The discoveries of 
Faraday and Henry were made as far back as 1831, but it was a 
full half -century later before humming dynamos began to pro- 
duce the first electricity for lighting our cities. 

Now the situation is far different. Great laboratories are oper- 
ated by industries, so that the scientist and the man in industry 
are closely in contact: each can appreciate the work of the other. 
This association of industry and research has not lessened the 



quality of the latter it has in fact improved it. Merely to spend 
large sums of money does not guarantee scientific discoveries; 
the man himself is still the most important factor; but even a 
good man can do still better with adequate technical equipment. 
This sometimes is so expensive that only a large corporation can 
afford to invest in it. Equipment for creating artificial lightning 
is an instance. It is difficult to imagine that any college or uni- 
versity would have spent what it costs to produce lightning of 
10,000,000 volts. Yet the equipment has been made and put to 
such good use that lightning, now that it has been studied under 
controlled conditions, no longer offers the hazards to the trans- 
mission of electrical power that it did a few years ago. With 
increased reliability of transmission it has become possible to 
use larger and larger generating units, such as those at Grand 
Coulee Dam, or at Muscle Shoals. 

It might be supposed that research by industry would not be 
concerned with fundamentals; that emphasis would be centered 
on investigations showing some immediate likelihood of profits. 
However, in firms with the most enlightened research policies 
this is not the case; for it is realized that fundamental knowledge 
obtained today may lead to entirely unforeseen applications to- 
morrow. There is the oft-told story of Faraday, who was asked 
by Gladstone what use his discovery of electromagnetic induc- 
tion would have. In reply, the scientist asked the statesman: 
"What use is a baby?" That particular baby grew up into the 
electrical industry of the present time and it is still growing. 

In addition to what the corporations are doing there is the 
great amount of important research being carried on by the 
Federal Government; at the National Bureau of Standards, for 
example, or in the Department of Agriculture and the Coast and 
Geodetic Survey. Also, many of the universities now co-operate 
with industry, perhaps making use of the fellowship system in- 
augurated by Robert Kennedy Duncan, first director of the justly 
famed Mellon Institute at Pittsburgh. Under that system it is 
possible for a firm of relatively small size, which could at the 
best set up a laboratory for only two or three men, to establish 


a fellowship at a central research institution. The fellow, sup- 
ported by the business organization, has the advantage of associ- 
ation with other scientists, and of the use of superior equipment 
which includes not only the laboratories but also the library and 
machine shop. The findings of the fellow are at the disposal of 
the donor; and even many large companies which maintain full 
research staffs of their own have taken advantage of facilities 
such as those afforded at the Mellon Institute. 1 

In the following pages we shall see several instances of indus- 
trial research into fundamental principles, performed without 
any direct thought of application for profit. Yet applications 
appeared when the knowledge was obtained. Thus, when Dr. 
Kenneth D. Hickman studied the problems of distillation in a 
high vacuum, his findings led to the discovery of a means of 
carrying on the commercial distillation of vitamins from fish 
oils. This was far removed from the interests of the photo- 
graphic concern for which Hickman worked, so a subsidiary 
company was established to utilize his process in fish-oil 
distillation. In the laboratory of another corporation Dr. Irving 
Langmuir worked for years on gases which seemed to come 
out of hot filaments, until his conscience troubled him about 
spending so much time on a task which showed so little promise 
of results. Yet directly from Langmuir 's work came modern 
incandescent lamps which, compared to their predecessors, 
operate at a saving of millions of dollars nightly. And for several 
years Wallace H. Carothers studied the behavior of long chain- 
like molecules, seeking merely to learn all he could about them. 
Yet from Carother's research comes nylon and a whole family 
of related fabrics superior to silk, which they are replacing in 
the manufacture of gunpowder bags and parachutes, as 

1 By far the most complete summary of industrial research is the 370-page 
report prepared by a special committee of the National Research Council, and 
issued in 1941 by the National Resources Planning Board. This showed, as of 
1940, that 2350 companies in the United States operated a total of 3480 labora- 
tories, employing 70,033 persons. More than half of this number are professionally 
trained. Chemists are most numerous, with 22.4 per cent of the total, but en- 
gineers run a close second with 21.4 per cent. 


surgical sutures, and for the stringing of pearls and tennis 

At war or at peace, then, our world of today is a very different 
place from what it was a few generations ago. Thanks to 
scientific research new jobs, new processes and new industries 
have come into being. No matter how isolated he may be, no one 
alive today has been wholly immune to their influences. The 
complete story of these studies and their results is told in count- 
less reports to technical societies, in patents, in scientific books 
and journals. But this mass of material, though it is available in 
the nation's libraries, is hardly in a form convenient for con- 
sultation by most of us whose lives it has affected so greatly. 

In this book it is the author's aim to tell the story of a few of 
the more important scientific developments of our day. 
Obviously it will be necessary to omit much that might have 
been included; but it is hoped that these chapters will give the 
reader some idea of typical ways by which, in its many branches, 
science is remaking our world. Physicists, chemists, biologists, 
psychologists, men and women in all branches of science have 
taken part, though perhaps the best-known scientific dis- 
coverers of the past few years have been concerned with 
chemistry. So, before we start on our explorations, let us get 
acquainted with some of the chemist's tools. 

Fundamentally, the work of the chemist is to rearrange 
atoms. Of course atoms can be rearranged without his services 
they were, long before the chemist appeared. When anything 
burns, atoms are moved about. And life, even the most primitive, 
is itself made possible only because of the atomic shifts that 
occur in living cells. 

When the sun's rays fall on water in ocean or lake and evap- 
orate it, no rearrangement of atoms happens in the process. The 
vapor is carried in the air over land, where it may be cooled and 
fall as rain, going into rivers, perhaps dropping over waterfalls 


on the way back to the ocean; but the molecules, the units of 
which water is made, consist of building blocks still smaller 
the atoms, of which nature has 92 separate kinds. A water mole- 
cule contains three such atoms. Two of them are alike; they are 
hydrogen atoms, while the third is oxygen. To indicate this, the 
chemist calls water H 2 O. No matter whether water is in liquid 
form as in lake or ocean, or in vapor form as in the atmosphere, 
it still consists of these same three atoms. 

But the chemist can perform an experiment with water in 
which electricity pulls the hydrogen and oxygen atoms apart. 
If two pieces of metal are connected to a source of electricity 
and immersed in a jar of water as it comes from the tap, bubbles 
soon begin to appear around them. The bubbles may be 
collected separately, and we then have two gases which are 
quite different one will burn, the other will not. The former is 
hydrogen, the latter is oxygen. With one of the chemist's most 
useful tools has been performed the seemingly magical experi- 
ment of converting a liquid into two different gases. If we wish, 
we can collect hydrogen and oxygen from this process, which is 
called electrolysis, and recombine them. Electricity can again 
cause the joining, for an electric spark, inside a glass tube con- 
taining the two gases, will make them explode, and inside the 
tube small drops of water will appear. 

Also heat, as from a match flame, might initiate the recombi- 
nation. And indeed heat, in the form of fire, is the oldest of the 
chemist's agents and is still his most important one. That is why 
every laboratory table has on it a Bunsen burner a type of gas 
burner, similar in principle to the one in your gas range, which 
burns the gas without making smoke. Incidentally, it burns 
without much light either, for the illumination which the old- 
style open gas flame gave resulted from the heating, by the 
flame, of the smoke particles caused by incomplete burning. 
Illuminants were put into the gas to increase the number of 
these glowing particles. 

Chemical changes are, in general, speeded by heat, and that 
is why heat is important to the chemist. The speed of a chemical 


reaction is approximately doubled for every increase in temper- 
ature of 18 degrees Fahrenheit. This speeding up is responsible 
for the mysterious fires caused by "spontaneous combustion." 
A big pile of coal, of oily rags, or even of hay, may thus take 
fire. Burning of any kind is simply the joining of atoms with 
oxygen; and oxygen usually comes from the air, of which it forms 
about a fifth part. Even at ordinary temperatures the joining of 
oxygen atoms liberates a small amount of heat, so our pile of oily 
rags tends to get a little warmer. Especially if the pile is a large 
one, and not ventilated, the warm air accumulates. Then, as it 
gets hotter, the reaction is accelerated, and as it accelerates 
there is still more heat given off. So the temperature may 
gradually work up until it reaches the combustion point and the 
pile begins to blaze. Fire, or combustion, is merely a very rapid 
form of oxidation, with the liberation of light and heat. 

The temperature of a flame is less or more intense, depending 
on what is burning. The hottest, that of oxygen and acetylene in 
a special torch used for cutting through metal, reaches 5500 
Fahrenheit. At the other extreme is the Aflame of cotton soaked 
in a mixture, in correct proportions, of carbon disulfide and 
carbon tetrachloride. This makes a flame well below the boiling 
temperature of water; in fact, it is possible to hold the burning 
mass in the hands without discomfort. 

As a simple example of the use of heat in aiding a chemical 
reaction, we might take the way the French chemist Lavoisier 
first separated oxygen from the air. For many days he heated 
some mercury ( quicksilver ) in a retort in which air was present, 
and finally a red powder appeared on the shiny surface of the 
liquid metal. This was mercuric oxide, made up of molecules in 
which mercury and oxygen atoms combined. But when the red 
mercuric oxide was heated to temperatures much higher than 
those he had used at first, it changed back to mercury, and 
oxygen was given off. Indeed, it was by heating the red oxide 
with the sun's rays concentrated by a huge burning lens that 
the English clergyman and chemist, Joseph Priestley, had 
discovered oxygen in the first place. Nowadays, however, 


chemists have much more convenient sources of heat for speed- 
ing their reactions. If the gas flame of the Bunsen burner is not 
hot enough, hotter flames are used, or else the electric arc, 
which gives controllable temperatures of many thousands of 
degrees Fahrenheit. 

In most chemistry courses today, one of the first laboratory 
experiments is the preparation of oxygen; but Priestley's method 
is not used. Instead, a mixture of potassium chlorate and manga- 
nese dioxide is put in a test tube and heated. Oxygen results. 
Potassium is a soft, white, silvery metal and, in the chlorate, 
its atoms are combined with those of the gases chlorine and 
oxygen. Manganese is a heavy, grayish metal, and is com- 
pounded with oxygen to form the dioxide. 

After one has obtained all the oxygen possible from heating 
a mixture of these compounds, an examination and analysis of 
the material remaining in the test tube would reveal there the 
presence of potassium chloride, for one thing. This is simply a 
combination of potassium and chlorine the oxygen that was 
present in the chlorate having been given off as gas. But what 
about the manganese dioxide? Surprisingly enough, that is still 
present, after the reaction, and unchanged. But if, thinking the 
manganese dioxide unnecessary, you tried to make oxygen 
merely by heating potassium chlorate, you would have a hard 
time getting any. 

The manganese dioxide plays the part of a catalyst, which is 
perhaps the most "magical" of all the aids employed by the 
chemist. A catalyst is a substance which speeds ( or, sometimes, 
retards) a chemical reaction, but which in the end remains in 
its original form. Various analogies have been used to describe 
such substances. They have been called "chemical parsons" for, 
like the clergyman performing a wedding ceremony, they 
"marry" atoms. Another analogy has been used by Dr. Roger J. 
Williams, of the University of Texas. Pointing out that chemists 
often express in simple form what happens in a chemical change 
by writing the first substance, then an arrow, then the second 
substance, he said that the catalyst "lubricates the arrow." 


In a great number of chemical processes used in industry, 
catalysis plays a vital part; and catalytic agents will often be 
mentioned in later chapters. Most sulfuric acid today, for ex- 
ample, is made by the "contact process." Sulfur dioxide, which 
can be made by burning sulfur, is mixed with air, then passed 
through tubes containing a catalyst, such as finely divided 
platinum or ferric oxide, which makes the dioxide into sulfur 
trioxide by adding atoms of oxygen from the air. The trioxide 
dissolves in water to form sulfuric acid. In making ammonia by 
the Haber process, as we shall see later, finely divided iron is 
the catalyst which makes nitrogen combine with hydrogen. 
Nickel is the catalyst used in commercial 'Tiydrogenation" 
processes to make liquid fats react to form solid fats. Hydro- 
genation has also been applied in the Bergius process to make 
petroleum and its products, such as gasoline, from coal and 
hydrogen. This is the German development which provided 
much of the fuel needed for Hitler's mechanized warfare. 

Just what a catalyst does is still a problem, and much chemical 
research has been expended in hunting for an answer. There are 
really two kinds of catalysis. In one there is a reaction of the 
catalyst with one of the original compounds; and this in turn 
reacts with the second. In this final change, the catalyst itself is 
regenerated. Such a process takes place throughout the mixture; 
and in general, the more catalyzer there is, the faster the re- 
action goes. 

The other kind is surface catalysis, and makes use of a solid 
divided into very fine particles so as to give a great deal of 
surface. Finely divided platinum, vanadium, nickel or very 
porous charcoal are among those often used. This time the raw 
materials of the process, such as the sulfur dioxide and the 
oxygen in the contact process of making sulfuric acid, link them- 
selves to the platinum atoms on the surface of the particles; 
and in this state they can unite with each other, whereas out in 
the open they could not. Here, again, an intermediate com- 
pound is formed, but it is in a layer, only one molecule deep, on 
the surface of the catalyst. This is why the surface has to be as 


large as possible. Not only is the catalyst finely divided, but also 
fine cracks in the particles, perhaps too small to be seen even 
with the microscope, increase it still further. 

Catalysts, like animals, may be poisoned, and with some of 
the same poisons, too. Arsenic, for example, even if present in 
minute traces, will make the platinum catalyst inactive. It seems 
to do this by taking hold of the loose electrons in the surface of 
the platinum and joining with them to form a layer of a com- 
pound of platinum and arsenic. As this layer is only one mole- 
cule deep, a very small amount of arsenic will cause such 
poisoning; there are then no loose electron handles for the sulfur 
dioxide or other molecules to grab. But the catalytic action of 
platinum, after arsenic has destroyed it, can be restored by 
treating it with strong nitric acid. 

The efficacy of platinum in this spongy condition in acceler- 
ating reactions is shown by the way it makes hydrogen and 
oxygen unite to form water. In fact, if you have a mixture of the 
two gases and toss in a bit of spongy platinum, the gases come 
together with a loud explosion. Such material also causes the 
ignition of coal gas in air. In this form it has been used for a 
gas lighter, and also in a cigarette lighter, where it ignites 
alcohol vapor. 

Of particular importance to our life processes are catalysts of 
the class called enzymes, formed in living cells. Without them, 
cells could not carry out the chemical reactions of their life 
processes at the proper speed unless the temperature was much 
higher. Enzymes are responsible for the changes that take place 
in digestion. This starts in the mouth. In saliva there is an 
enzyme called ptyalin, which has the function of converting 
starch in the food into a sugar. This is not ordinary sugar but 
another member of the same class of carbohydrates, called 
maltose. In the small intestine another enzyme, maltase, con- 
verts the maltose into glucose, which the body absorbs through 
the intestinal wall. Other kinds of foods are digested, thanks 


to other enzymes; and even such biological processes as repro- 
duction and heredity, it has been suggested, are caused by the 
action of these catalysts. 

Industrially, the enzymes are used under controlled condi- 
tions the oldest of such applications, perhaps, being in the 
baking of bread and the brewing of beer. In beer brewing, the 
first change is very similar to what happens to the starches in 
the mouth. The barley contains starch, and before use it is al- 
lowed to germinate. This produces the enzyme diastase, which, 
like ptyalin, converts starch into maltose, and also into malto- 
dextrin and dextrin. These, in turn, are acted on by zymase, 
which is present in yeast; and alcohol is the product. This oc- 
curs, as it does in many of the processes in which the enzymes 
play a part, by hydrolysis the union of water with the original 
material. Usually, in brewing, conversion to alcohol is not fully 
carried to completion, and some sugars remain. The longer the 
process continues, in general, the less sweet the beer will be. 

The process by which meat becomes tender as it is stored is 
also carried on by enzymes. This "tenderizing" can be hastened 
by the use of papain, which is present in pineapples and is also 
obtained from the papaya. Another group of enzymes is respon- 
sible for the blackening of an apple or potato when cut and 
exposed to the air. Then the reaction involves union with oxy- 
gen instead of water. 

A striking feature of the work of enzymes is the exceedingly 
minute amount needed to accomplish die result. For instance, 
invertase, which converts ordinary sugar into two others, fruc- 
tose and glucose, is so potent that it will initiate the change in 
a million times its own weight of sugar. 

One might list many more items among the so-called "magic 
wands" of the chemist. Seemingly magical in their action, to 
the layman, are such agents as the indicators, which tell by a 
change in color how acidic or alkaline a mixture is, and which 


play an important part in much of the chemist's work. Then too 
there is the process of "fractionation," by which molecules can 
be sorted out, even though they are not changed in the process. 
This has to do with the different boiling points of substances 
which may be mixed, as are the various compounds of hydrogen 
and carbon in the oil that pours out of oil wells. The first sepa- 
ration of gasoline is done by such fractionation. After that, using 
catalysis and other methods, the other fractions, with both 
higher and lower boiling points, can likewise be converted into 
gasoline, a process to be described in detail in a later chapter. 

But, magical as these chemical agents and processes may ap- 
pear, that word can hardly be applied to them. Chemistry was 
once mixed up with magic. That, however, was in the days 
when chemists were still called alchemists and sought, by spells 
and incantations, for the philosopher's stone which, so they 
thought, would in a minute quantity change lead into gold. The 
alchemists never succeeded, but they did acquire much infor- 
mation which laid the foundation upon which the real science 
of chemistry arose after spells were banished from the labora- 

Surely the wonders that can be accomplished with catalysts 
and enzymes are even more marvelous (and of considerably 
more practical value) than what the philosopher's stone might 
have done. Yet the curious thing is that, without magic, the 
ancient dream of the alchemists has been realized: even the 
transmutation of one element into another into gold has 
been accomplished in the newest kind of chemistry. This kind 
goes beyond the atom, into its very nucleus, and there, with 
powerful atom-smashers, produces fundamental changes. How- 
ever, before we hear about that, let us see some of the achieve- 
ments of the older kind of chemistry, which still is turning out 
gasoline, foods, explosives, rubber and all the other products 
vital to our civilization, whether at war or in peace. 

II. Explosives in Peace and War 

When we think of explosives, most of us think of war of 
the bombs, shells, cartridges and other carriers of substances 
that go "bang." Yet the two billion pounds of explosives ex- 
pended by the Allies during World War I did not exceed the 
amount that the United States used in a like length of time, 
from 1936 to 1940, for pacific purposes. In other chapters we 
shall see how the petroleum, mining and metal industries have 
made our civilization possible. But those industries could not 
have reached their present position, where they are indispensa- 
ble to our national existence, without the help of explosives. 

Alfred Nobel invented dynamite in 1867. When it was ap- 
plied to the mining of copper, for example, the production of 
that metal proceeded with enormous acceleration, thus keep- 
ing up with demands for copper from a rapidly growing elec- 
trical industry. In recent years, under normal conditions, our 
annual use of explosives in the United States has been between 
300,000,000 and 500,000,000 pounds, of which about a third is 
expended in coal mining, a fifth in mining other ores, a sixth in 
quarrying rock and the rest in clearing stumps from land, build- 
ing roads and tunnels, and opening ice jams in rivers. 

Practically all explosives that are commonly used contain 
nitrogen and, in preparing them, nitric acid is employed to in- 
troduce this important element. In earlier days the acid was 
made from deposits of saltpeter that is, potassium or sodium 
nitrate. Natural saltpeter deposits were too limited, however, 
to meet the demand for an indefinite time. So men looked long- 
ingly into the atmosphere, of which about four-fifths consists 
of nitrogen, with some 20,000,000 tons of the gas above every 
square mile of the earth's surface. 

When lightning flashes, the electrical discharge causes some 



of this nitrogen to combine with a portion of the oxygen which 
forms the other fifth of the air. Nitric oxide is the result. As this 
cools, more atoms of oxygen are extracted from the air, and the 
result is nitrogen dioxide, a reddish-brown gas in concentrated 
form. This gas ( NO 2 as the chemist writes it, to show that two 
oxygen atoms are combined with one of nitrogen) readily com- 
bines with water, H 2 O, made of hydrogen and oxygen, to form 
HNO 3 , or nitric acid. Since lightning usually occurs in connec- 
tion with rain, this process takes place in every thunderstorm, 
and much of the rainfall in such a storm is actually very dilute 
nitric acid. A great deal of the nitrogen required for natural 
plant growth becomes fixated in this way. According to one 
estimate it amounts annually to 1,500,000,000 tons of nitrogen. 

In 1903 the process was imitated by man, when two Nor- 
wegian chemists, Kristian Birkeland and Sam Eyde, prepared 
nitric oxide, and from it nitric acid, with an electric arc spread 
out into a disc six feet in diameter. This was the first successful 
process for the fixation of atmospheric nitrogen and was quite 
widely used, especially in Norway and other countries where 
abundant water power made electricity cheap. Since then, how- 
ever, processes not requiring such a large amount of electrical 
energy have largely replaced the Birkeland-Eyde process, even 
in Norway. Today the process most widely used is one de- 
veloped during World War I, when Germany's supply of salt- 
peter from Chile was cut off and nitrogen was needed for war 
explosives. Fritz Haber was the chemist mainly responsible. It 
is also known as the "synthetic ammonia" process, since am- 
monia makes possible one of the main steps. 

Nitrogen boils at 195 Centigrade, and oxygen at 183 
Centigrade. Thus, when air is liquefied, nitrogen boils off first 
and liquid oxygen remains. This convenient means of separat- 
ing the gases in their pure form from the atmosphere is used to 
secure nitrogen for the Haber process. Hydrogen is obtained 
from water by the action of an electrical current. Then the 
hydrogen and nitrogen are forced, under pressures two hundred 
times that of the atmosphere, into huge cannonlike steel cylin- 


ders, where the temperature is 500 Centigrade. Under these 
conditions, and with the aid of our friend the catalyst in the 
form of porous iron, many of the nitrogen atoms unite with 
three hydrogens to form NH 3 , which is ammonia. This is fa- 
miliar to everyone in the form of ammonia water, used in the 
household. At a temperature of 600 Centigrade again in the 
presence of a catalyst, platinum this time ammonia will com- 
bine with oxygen from the air to form nitric oxide, and this is 
the second step in the Haber process. Then, as with other meth- 
ods, the nitric oxide combines with more oxygen to form nitro- 
gen dioxide and that, with water, to form nitric acid. 1 

Though nitrogen goes into most explosives, other elements 
are needed too; and the demands of war require explosives of 
many kinds. Even a single shot from a 14-inch coast-defense 
gun uses several. The kick to drive the projectile on its way 
comes from hundreds of pounds of smokeless powder. In the 
projectile itself there may be a bursting charge of a few hun- 
dred pounds of high explosive. Perhaps there is a time fuse, 
to make it burst after a certain interval, and this will consist of 
a few pounds of old-fashioned black powder. But usually the 
shell explodes when it hits then there is a detonator, of mer- 
cury fulminate. And to set off the high explosive there will be 
a booster charge of another explosive even more powerful. 

The bursting charge is an explosive that goes off with great 
rapidity, building up its full pressure at once. This shatters 
the shell into fragments, which produce a maximum amount of 
damage. But if such an explosive were used in the gun barrel, 
the gun likewise would burst with disastrous results. Smoke- 
less powder, used for the propelling charge, goes off more 
gradually. It does not really explode but undergoes extremely 
rapid burning. Expanding gases in the barrel cause a more 
gradual building up of pressure behind the shell, accelerating 
it from rest, at die start, to its full speed at the mouth. 

1 This method has been used to produce enormous quantities of nitric acid, 
to supply our war needs, by the Du Pont Company, by the Allied Chemical and 
Dye Corporation and others. 


The first propelling explosive was gunpowder, a mixture of 
powdered charcoal, sulfur and potassium nitrate (saltpeter). 
Roger Bacon, the Franciscan friar, is supposed to have made 
it in 1264. According to tradition a German monk, Berthold 
Schwarz, first used it in a cannon to hurl stones. As early as 
1340 there was a powder factory in Augsburg, Germany. At the 
battle of Crecy, in 1346, gunpowder and wooden cannon helped 
Edward III of England defeat Philip of France. And much 
earlier than any of these dates, in the ninth century, the Chi- 
nese are believed to have had gunpowder which they used in 
fireworks. Apparently they never thought of using it to kill 

Black powder, the modern form of gunpowder, is a burning 
explosive. Ignited by heat, as from a flame, the nitrate furnishes 
oxygen to supplement that of the air. The charge burns with 
great rapidity, the gases being generated as burning progresses. 
In any explosive these heated gases, many times the volume of 
the original solid or liquid, produce the effects desired. 

By mixing glycerine, used in soap-making, with nitric and 
sulfuric acid, nitroglycerine is produced, as Ascanio Sobrero, 
an Italian, discovered in 1846. The chief use of the material, 
until Nobel introduced dynamite, was in medicine as a heart 
stimulant. A slight shock will explode nitroglycerine, but Nobel's 
great contribution was to mix it with an absorbent material; it 
can then be transported and handled. Originally an inert ma- 
terial called kieselguhr a form of earth composed of the skele- 
tons of minute organisms was used, but this has been super- 
seded by other materials. Sometimes, too, the nitroglycerine 
is mixed with gelatin to form blasting gelatin, an explosive 
widely employed in construction work. These explosives are 
set off by a detonator, such as mercury fulminate. 

Born at about the same time as nitroglycerine was nitro- 
cellulose, or guncotton, made by treating cotton with nitric 
acid. This was most temperamental, as the Austrians who 


started making it in 1845 found when they blew up more of 
their own factories than they did of the enemy's works. Mixed 
with nitroglycerine, vaseline and acetone, however, nitrocellu- 
lose is made into smokeless powder, which is more tractable. 

Actually "smokeless powder" does make some smoke and it 
is not a powder. Flakes, strips, cylinders or pellets are the most 
usual forms. Cotton is the usual raw material, though any form 
of cellulose will do. In early World War I days, the British 
thoughtlessly allowed Germany to import cotton, apparently 
not realizing what it would be used for. When they did wake 
up, and the cotton supply was blockaded, the Germans used 
wood pulp instead. 

High explosives do not burn. They are fired by the shock 
from the detonator which is transmitted as a wave through 
their mass; and there is then an instantaneous molecular rear- 
rangement, a transformation from solid to a gas which has far 
greater volume. This change is so quick that the gases have no 
time to escape from the container, even if there is an opening; 
and so the walls are shattered. 

The first high explosive to be used extensively was picric 
acid. This dye, made from coal tar, gives to the hair and skin 
of men who work with it a yellow color which will not wash 
off, though the color disappears when they are no longer in 
contact with the materials. One great danger in using picric 
acid is the likelihood of its combining chemically with the 
metal of its container. Compounds are formed which may go 
off spontaneously, and then the rest of the explosive in the 
container goes off too. 

Though, for such reasons, the use of picric acid itself as an 
explosive has been largely abandoned, it is still a step in the 
manufacture of ammonium picrate, which the U. S. Army em- 
ploys under the name of "Explosive D." A detonation wave 
moves through a mass of ammonium picrate at a speed of 4.5 
miles per second, producing a very rapid shattering action 
what the ordnance officer calls "brisance." It is therefore used 




(see page 11) 

\ ^ 



(see page 19) 


to fill armor-piercing shells such as are fired from big naval 
and coast-defense guns. 

Though the detonation wave travels through it more slowly, 
TNT, the common name for trinitrotoluene, is the most widely 
used high explosive today. Actually it has less power than Ex- 
plosive D, but it stands much rougher treatment. A bullet can 
be fired through TNT without exploding it. In appearance 
something like brown sugar, it melts at 176 Fahrenheit and 
pours like hot tar. 

Coal tar was the original source of the raw material, toluene, 
which is treated with sulfuric and nitric acids. But of recent 
years plants have been erected in the United States for manu- 
facturing toluene from gasoline. Since the material in the gaso- 
line from which toluene is made is one of the things respon- 
sible for an engine's knock, the motorist gets a better grade of 
gasoline as a result of the extraction. There is plenty of raw 
material; for it is estimated that a gasoline production of 2,500,- 
000,000 gallons yearly, a tenth of what it was in pre-war times, 
would be ample' to furnish 2,000,000 tons of TNT. 

Exploding TNT gives off a dense black smoke, because some 
of the carbon atoms of which it is made remain uncombined in 
the reaction, and these black particles float in the air. But when 
it is mixed with ammonium nitrate, we have the explosive called 
"amatol," used in shells and bombs. This is so insensitive that 
the usual practice, in plants where these shells are filled, is to 
drill a hole in the explosive with an ordinary pneumatic drill! 
Into this is placed the booster charge. 

The very sensitive detonator, mercury fulminate, will not 
set amatol off, and that is why a booster is needed. When the 
shell strikes, the fulminate explodes and sets off the booster 
either TNT or another explosive called tetryl. That in turn de- 
tonates the amatol; all, of course, in far less time than it takes 
to describe the process. 

Lead azide is another compound used as a detonator instead 
of mercury fulminate. It is less likely to go off accidentally, and 


it does not require mercury, most of which comes from Spain. 
There is plenty of lead in the United States. 2 

In addition to the use of explosives as a propellant in guns, 
there have been many proposals for electric cannon, with mag- 
netic coils, or solenoids, pulling a steel projectile through the 
barrel to start it on its way. In fact, explosives are fairly ex- 
pensive sources of power, the same amount of which can be 
produced much more cheaply as electricity. But the trouble 
with electric cannon, which sometimes look most attractive on 
paper, is that the power cannot be released as quickly as with 
an explosive, unless with very elaborate and expensive equip- 
ment, like that for artificial lightning. Then the lack of port- 
ability is another objection; so the electric cannon has never 
proved practicable. 

Many peacetime uses of explosives have, fundamentally, the 
same object as their use in war that is, to move large amounts 
of material easily and quickly. Blasting earth for reservoirs, cut- 
ting through mountains for tunnels and railroads, demolishing 
old buildings before new construction; all these are essentially, 
though from different motives, what the military explosives are 
employed for. 

2 Probably the most important name in the American explosives industry is 
that of Du Pont. The founder of the company, Eleuthere Irenee du Pont, learned 
about explosives when, in 1788, the famous French chemist Lavoisier took 
him into the royal powder works at the age of seventeen. After being imprisoned 
three times in the French Revolution, young du Pont managed to come to 
America with his father and a brother. At first intending to start a company 
for speculation in land, he noticed the poor quality of American gunpowder, 
and set up his own powder mill on the Brandywine Creek near Wilmington, 
Delaware. This was successful from the start. It furnished, for example, much 
of the powder used in the war of 1812. During the latter half of the nine- 
teenth century and the first few years of the twentieth, the Du Pont concern 
grew tremendously, as did many others. In 1907 the Federal Government, under 
the Sherman Anti-Trust Act, prosecuted the company and forced its dissolution 
into three parts. These are Du Pont, Atlas Powder Company and Hercules 
Powder Company. In 1933 the American Cyanamid and Chemical Corporation 
organized an explosives division, and these four companies became the largest 
present-day explosives manufacturers. All of them, however, are important 
chemical manufacturers, with explosives as just a part of their total production. 


In peacetime, corresponding most closely to the use of ex- 
plosives as a propellant in guns, there are guns that have no 
lethal powers unless they go off accidentally. The "velocity 
power tools," made by the Mine Safety Appliances Company of 
Pittsburgh, are really guns. One, for instance, is a punch that 
can be used to make a rivet hole in a half -inch steel plate. It 
does not look much like a gun, but is a piece of steel, shaped in 
the form of an extra-fat letter C. A cartridge, similar to an or- 
dinary blank cartridge, is inserted, the jaws of the C are placed 
over the plate to be punched, and the firing pin, on top, is given 
a tap with a small hammer. The cartridge explodes and the ex- 
panding gases, exerting pressure of 100,000 pounds, push the 
punch through the plate, leaving a smooth, round hole. One 
man can punch holes in girders with such a gun at a rate of 
thirty to fifty an hour. 

A somewhat similar device, with a sharp edge that will sever 
a steel-wire rope an inch in diameter, is used for cutting cables. 
Rivets can be driven with a gun in which the cartridge explodes 
to drive the hammer against the rivet. Another device is an 
explosive-driven punch to drive rivets out of a structure. The 
illustration shows a cable splicer powered by explosive, in use 
by a lineman. 

In all these velocity power tools the piston on which the 
expanding gases push is the bullet but, unlike ordinary guns, 
it never leaves the barrel. Since the gases are retained in the 
barrel, much of the noise of the explosion is eliminated. 

A new method of using explosives for riveting was intro- 
duced to American industry in the summer of 1941, and has 
since been extensively applied in building airplanes and other 
war equipment. In a big all-metal bomber there are as many 
as 10,000 fastening points where rivets must be inserted, but 
which are accessible from only one side. Even a pursuit plane, 
of all-metal construction, has about eight hundred. In usual 
riveting, some solid support is held against the opposite side of 
the rivet to keep it in place as the hammer pounds on it and 
forms the head which holds it tight. With only one side acces- 


sible, however, complicated equipment was needed, and a 
workman could place but three or four of these blind fastenings 
a minute. 

The new rivet, originally invented by two Germans, Karl and 
Otto Butter, connected with the Heinkel airplane works, was 
brought out in the United States by Du Pont, who control the 
American rights. Two years' experimental work by Du Pont 
engineers brought it to a high degree of perfection. The design 
had to be adjusted to our standards; and equipment for con- 
trolling accurately the tiny amounts of explosive was planned 
and built. During 1940 the rivets were tested by the U. S. Army 
and Navy. Then a limited number were sold to a few large 
airplane manufacturers for actual trials. 

The rivet, of aluminum alloy, looks at first glance like one 
of the usual kind. However, in the shank end there is a small 
cavity, in which there is a charge of explosive. In use, the rivet 
is placed in the holes made in the pieces of metal to be joined. 
Then an electrically heated riveting iron with a silver tip is 
touched to the rivet head. The heat transmitted through the 
rivet sets off the explosive, which spreads the shank to form 
a head on the other end, and the rivet is in place, installed in 
about two seconds. After the holes are prepared, a single work- 
man can place fifteen to twenty rivets per minute. 

The explosive charge is so accurately controlled that the ex- 
pansion which it produces can be held to within limits of a 
fiftieth of an inch, state Du Pont engineers. They say that a 
large part of the great advance in aviation has been made pos- 
sible by the all-metal design, using lighter metals, such as 
alloys of aluminum and magnesium. This, of course, requires 
thousands of rivets. In the Douglas B-19 bomber, the largest 
ever built, there are some 3,000,000 rivets. Many of these can 
be reached from both sides and installed in the usual way; 
but designers were hampered by having to keep this in mind, 
when other considerations might dictate construction requiring 
blind rivets. Thus it is expected that the new rivets will make 
possible great structural advances. They will have other uses, 


too, and will probably soon be made of other metals, such as 

With the tremendous need for its products, oil is now a sub- 
ject of great interest. Here, too, guns are used, not primarily 
for the protection of the wells against enemies but to increase 
the flow of the precious fluid. 

An oil well is not the mere hole in the ground that many 
picture. Going down perhaps several miles, the walls of the 
well are usually cemented, and inside the cement is a casing 
of steel pipe. In many oil fields there are several strata from 
which oil may be drained, so it is customary in that event to 
drive the well down to the deepest. This is simpler, and more 
economical, than drilling a shallow well, emptying one layer, 
then drilling farther, emptying the next, and so on. While the 
drillers are on the job, they go right to the bottom and install 
the casing all the way down. 

But oil cannot pass through a steel casing, and it is necessary 
to punch holes so the oil can leak through. The first device to 
accomplish this was a mechanical perforator, patented in 1903, 
consisting of a series of horizontal pointed pins, driven outward 
through the casing by a wedge pushed down inside. Then, in 
1926, a patent was granted for a device which used explosives 
to do the same thing. Since then the gun perforator has been 
widely used in oil fields throughout the country. 3 

This perforator looks no more like a gun than does the 
velocity power punch. It is a long cylinder, of diameter from 
three to five inches, depending on the bore of the well. The 
sides of the cylinder are studded with as many as 24 firing units. 
Each unit is really a little gun, with barrel, powder charge and 
pointed steel bullet. After the cylinder is lowered to the correct 
depth, the guns are fired electrically, one at a time. 

Since, however, the barrel must obviously be quite short to 
fit within the casing, there is a problem in getting the neces- 

8 Largely by Lane Wells, Inc., of Los Angeles. 


sary pressure behind the bullet. In a rifle the gases have the 
whole length of the barrel in which to expand and to build up 
their push. The perforator gun uses a quick-burning pistol 
powder, and the bullet leaves the gun so quickly that there is 
little time for this process to take place. Therefore, a shear disc 
is used a metal disc between the powder and the bullet. The 
charge explodes, the gas pressure increases until it is sufficient 
to break the disc, and the gases then give the proper wallop 
to the bullet, driving it out of the barrel and through the casing, 
perhaps several layers of steel and cement. 

When enough holes have been made in the casing, the per- 
forator is pulled up and the oil flows. Finally, after all the avail- 
able oil has been secured from this zone, a plug must be placed 
above that level in the well. If not, oil from a higher stratum 
would flow down, and out through the same holes. To place 
such a plug, the same rigging used for the perforator lowers 
the plug into place, with the setting tool above it. In this is 
another charge of explosive, set off electrically. The explosion 
releases a setting ram, which is driven down by a powerful 
spring, expanding the plug. A covering of synthetic rubber, 
which cannot be affected by the oil, holds tightly to the side 
of the well. Then the perforator is lowered again, holes are 
shot at the next level, and production resumes. 

The perforators have other uses, too. In some places, oil 
percolates through a limestone layer. No casing then is needed, 
but, to increase the flow of oil, the limestone is treated with 
acid to enlarge the pores. Before acid is applied, the guns are 
used to make holes in the limestone, thus enabling the acid to 
penetrate more freely. Also, the gun perforator has been used 
to increase the flow, at depths beyond 3,000 feet, of natural 
gas in a well near Amarillo, Texas, from which helium is ob- 
tained for the Navy's blimps. 

There are still other types of industrial guns. One, the sub- 
ject of several patents, is an explosive circuit breaker. A wire 
passes through the charge of explosive. If there is an overload 
the wire gets hot, the powder explodes, and the circuit is 


broken. One form of the device, patented in 1938, has a blank 
cartridge which separates the contacts when it explodes and 
also forces an insulating liquid, such as oil, between them, 
snuffing out any arc that might form. 

Explosives play their part, too, in the finding of oil. Science 
has learned much about the structure of the earth by the way 
earthquake waves travel through its interior. In the same way, 
by making artificial earthquakes with explosives, oil geologists 
can often tell whether conditions below the surface of the 
earth are such that oil might be present. Seismographs some 
distance away record these waves, and the records then reveal, 
to the initiated, the character of the structure below the sur- 
face. Explosives thus have made it possible to predict the loca- 
tion of sulfur, oil, gas and even metals with considerable ac- 
curacy, at a great economy in time and expense. 

III. Fuel for Tomorrow 

Probably no better example of the growth of a vast industry 
using and processing a product formerly discarded can be 
found than in the case of the refining of gasoline from petroleum 
and in the thousands of new compounds, many of great use 
and importance, derived from the same source. In the year 
1859 there were seventy-eight "coal oil" and kerosene plants 
in the United States, employing fewer than 1500 workers who 
turned out their product to the value of $6,398,000. In 1940, 
however, $11,000,000,000 represented the total value, at the 
wells, of U. S. petroleum production, and the finished value 
was far higher. 

In some way, vegetation in ages long past solidified to form 
deposits of coal, which is largely carbon. But by a process, the 
details of which are still a puzzle, some of the carbon atoms 
united with hydrogen to form what chemists call hydrocarbons. 
The simplest such compound is a gas called methane, which is 
made up of molecules each consisting of a carbon atom with 
four hydrogen atoms branching out from it. This is known as 
"marsh gas/' for it is produced by decaying vegetation in 
marshes. If you have two carbon atoms linked together, there 
can be six hydrogens attached to the pair, and then you have 
another gas, called ethane. With three carbons and eight hydro- 
gens, you get propane, also a gas. 

There is a whole series of these hydrocarbons, with the num- 
ber of hydrogen atoms always equal to two more than double 
the number of carbon atoms. The fifth member, called pentane, 
boils at about body temperature; below that it is a liquid. As 
the number of carbon atoms increases, the boiling point gets 
still higher; so does the melting point. By the time there are 



twenty carbons, the result is a solid at ordinary temperature. 
These higher hydrocarbons are commonly known as asphalt 
and paraffin. The liquids with the higher boiling points, having 
ten or so carbon atoms, make up kerosene; those of about seven 
or eight carbons, gasoline; and the gaseous ones are natural gas, 
piped from fields in Texas and Pennsylvania to many other 
parts of the country. 

When the first oil wells were dug, in 1859, kerosene was 
needed to supply the millions of oil lamps that lighted the na- 
tion's homes. So the crude petroleum was distilled and the 
kerosene separated. In those early days, the gasoline was thrown 
away, since nobody knew of any use for it. Even as late as 
1906 kerosene was the main product of the oil wells. But then 
the growth of the automotive industry increased the demand 
for gasoline; and as the production of gasoline, by the simple 
distillation process, forged ahead, there was left over more 
and more kerosene, as well as other compounds with the larger 
molecules. For them there was no market. 

In 1913 Dr. W. M. Burton perfected his cracking process, 
which was first commercialized by the Standard Oil Company 
of Indiana. This marked a revolution in the refining business, 
and for a quarter of a century it dominated refining methods. 

"Cracking" is just what its name implies; the larger mole- 
cules are divided into smaller parts. You cannot, for instance, 
just mix the parts together again and get what you started with, 
as you could with the products of straight distillation. In frac- 
tionation, after you had separated the kerosene, the gasoline, 
the paraffin, and so on, you could put them all back in a barrel 
in the right proportion, and you would have your crude petro- 
leum once more. But cracking is really more than this for in the 
process the molecules are actually changed. 

The yield of gasoline from a barrel of crude was more than 
doubled by the cracking method, which involves the use of 
both pressure and heat. Originally the temperatures used were 
about 700 Fahrenheit, and the pressure about six or seven 
times that of the atmosphere. But now temperatures of a thou- 


sand or more degrees, and pressures of 60 or many more at- 
mospheres a thousand pounds or more to the square inch 
are employed. These are applied in great towers, built like big 
guns to withstand the strain. 

Thus, in less than half a century, the oil industry has under- 
gone a complete reversal. The product that once was nearly 
useless is now of most value, and what was once the main 
product is converted into this former waste! 

An important economic advantage of the cracking process has 
been that seasonal demands may be met more easily. With 
fractionating, when gasoline in the crude was merely separated, 
the ratio between gasoline and fuel oil was always the same. On 
the other hand, in autumn and winter more fuel oil may be 
wanted but in spring and summer it is the gasoline that people 
desire. There would thus be a shortage of one and a surplus of 
the other, so a large storage capacity would be required. Now, 
however, the proportions may be varied with the seasons. In 
summer more heavy oil is cracked into gasoline than in winter, 
when oil is used more directly as fuel. Actually most big plants 
are combination cracking and fractionating units, and both 
processes are used. First the gasoline that will come off by dis- 
tillation is recovered in that way, and the remainder becomes 
"cracking stock." 

Cracking, applied to molecules, "makes little ones out of big 
ones"; but what about the still smaller ones, those made up 
of three and four carbon atoms, which are gaseous? The num- 
ber of these increases with cracking. When you break big rocks 
to make medium-sized ones for building, you have many still 
smaller fragments left over. Likewise, cracking produces frag- 
ments in the form of small molecules, which come off as gas. 
At one time this was used only as a fuel in the refineries. In 
some cases it was wasted, being simply burned as a torch at the 
end of a pipe in some safe part of the grounds. 

These molecules are now made into gasoline by a process 
that is the exact reverse of cracking. It is called "polymeriza- 


tion," and consists of putting together small atoms to make big- 
ger ones; and this is also being used today in an increasing 
number of refineries, generally in conjunction with fractionation 
and with cracking. 

Much of the gasoline for Hitler's mechanized war on land 
and in the air was produced by another synthetic process, the 
invention of Dr. Friedrich Bergius. This is called hydrogena- 
tion. Patents are held by the I. G. Farbenindustrie and, in the 
United States, by the Standard Oil Company of New Jersey, 
which built the first American plant in 1930, two years after 
one had appeared in Germany. In this country, high costs have 
restrained its development, but the Nazis were not so much 
interested in costs, since it made available for them gasoline for 
the Luftwaffe and oil for Diesel engines in naval vessels and 

The process can be used in refining crude oil, but its chief 
development, in Europe, has been with coal and products of 
coal tar as the source. Finely divided nickel acts as the catalyst 
which makes the reaction possible. Under great pressure (250 
times that of the atmosphere) hydrogen gas is made to unite 
with the molecules of the raw material, and the desired products 
are the result. There seems to be slight doubt that, without 
this process or one like it, Hitler would never have been in a 
position to plunge the world into war. However, it has also 
been used in England, in a plant which began operation in 
1935, having an annual capacity of 150,000 tons of gasoline. 
Perhaps this has been greatly increased and plenty of gasoline 
produced by the Bergius process may have made possible many 
of the R.A.F. raids on the country, and even the plants, where 
it was started. 

According to one report, 100 tons of dry coal, free from ashes, 
will yield by this method 62 tons of gasoline, 28 tons of useful 
gas, and a residue, partly ash and partly other carbon-contain- 
ing matter. Another hundred tons of coal, however, is needed 
to operate the equipment. 


Over a few decades the petroleum-refining industry has com- 
pletely changed. Before 1913 it was simply a business of proces- 
sing; all that the refiners did was to separate materials which 
nature gave them mixed together. But cracking, polymeriza- 
tion, hydrogenation, and many other related processes have 
turned refiners into chemical manufacturers. This has been 
made possible by chemical technology, which in turn has re- 
quired huge investments, both in original research and in the 
elaborate equipment demanded by the methods. Here again is 
an example of the way in which a large industry has been able 
to accomplish what the small independent producer could not 
possibly afford. 

Along with this improvement in the refining of gasoline has 
come another great achievement the elimination of "knock" 
and the production of the high-quality gasoline that is needed 
for modern aircraft. 

The 1912-model Cadillac offered the public several advances. 
The self-starter was one. But the ignition system of its engine 
was better, and the compression pressure was higher than had 
been used before. This resulted in greater power and efficiency. 
It had been realized that increased compression raised the ef- 
ficiency of an engine, and 1912 engines had double the pressures 
used originally, but this Cadillac was the first which actually 
reached the limit of the fuel indeed, it had not been realized 
that there was a limit! The result was that the engine began to 
knock, and engineers immediately realized that here was an 
obstacle in the path of further progress. So, in the laboratories 
of General Motors, under the direction of Charles F. Kettering, 
who was responsible for the self-starter, research was begun, 
to conquer knock. 

In the first stages, it was determined that knock was caused 
by gasoline in the cylinders burning so rapidly that the ex- 
panding gases actually pounded on the walls of the cylinder. 
Thus, it was not the engine but the fuel that caused knock. 


Next came the problem of eliminating knock, a task entrusted 
to Thomas E. Midgley, Jr., and his assistant, T. A. Boyd. It 
seemed as if making gasoline dark in color might reduce it, 
since excessive heat was a contributing cause and dark colors 
would absorb heat. Midgley and Boyd added a little iodine to 
the gasoline, and sure enough, the knock was gone. But iodine 
was expensive, and besides it had a bad effect on the engine. 
Then it was learned that color did not make the iodine effective; 
rather it was some quality of the material itself. 

More than 33,000 separate compounds were tried before the 
best was found. This is tetraethyl lead, a chemical that had been 
made in Germany. One chemical firm could supply it at a cost 
of $585 a pound! At that price about five dollars' worth would 
be required for a single gallon of gasoline, so tetraethyl lead 
was hardly practicable. But its high cost had been a result of 
rarity, and it was rare because there was no demand. The de- 
mand once created, it could be made from alcohol and lead at 
a reasonable cost. 

Still another chemical was needed. Tetraethyl lead, by itself, 
forms lead oxide, which deposits on the spark plugs, valve seats 
and stems. To prevent this, ethylene dibromide was added, to 
combine with the lead as it burned. Thus a gaseous compound 
was formed which would discharge with the exhaust. 

This step required in turn large amounts of bromine, and 
chemists looked longingly at the ocean. Even though sea water 
contains only about 66 pounds of bromine to a million pounds 
of water, there is still plenty of bromine there. So a ship, christ- 
ened the S.S. Ethyl, was fitted as a floating laboratory, and a 
practicable process for extracting bromine from sea water was 
devised. In 1933, ten years after the first ethyl gasoline had 
been placed on sale, a plant was established at Kure Beach, on 
Cape Fear, N. C., where coast and current conditions were 
favorable to providing the water and carrying away that from 
which the bromine had been removed. 

Ethyl fluid, now used in most of the gasoline sold, controls 
the rate of burning of the fuel. It prevents the gasoline from 


burning too rapidly, especially at high temperatures. Surpris- 
ingly enough, even though the motor runs cooler, it also delivers 
more power. The reason is simply that more heat units are 
changed into power, instead of being wasted through the ex- 
haust and the cooling system. 

The way the gasoline molecules are built out of atoms has 
a lot to do with engine knock. For example, there is one hy- 
drocarbon, called octane, which has eight carbon atoms in a 
chain. At the ends of the chain, and on each side of each 
carbon, hydrogen atoms are attached, making 18 hydrogens in 
all. This normal octane knocks very badly. Yet if the same 
atoms are switched around a little, with the chemist's seeming 
magic, the qualities may be vastly improved. Iso-octane has the 
same eight carbons and 18 hydrogens, but they are placed dif- 
ferently. Here there is a chain of five carbon atoms, from which 
other carbon atoms, with hydrogens attached to them, branch 
off. The more branches there are, in general, the better is the 

Iso-octane was once regarded as a "perfect" fuel, and from 
it we have the term "octane number." It has, by definition, an 
octane number of 100, while heptane, with an unbranched 
chain of seven carbon atoms to which 16 hydrogens are at- 
tached, is rated as zero. To determine the octane number of an 
unknown gasoline, it is burned in a single-cylinder test engine 
and compared with a mixture of heptane and iso-octane used in 
the same engine. The octane number is the percentage of iso- 
octane in the mixture which produces a similar amount of 
knock. Thus, if the knocking of a gasoline under test is equaled 
by a mixture of 70 per cent iso-octane and 30 per cent heptane, 
it has an octane number of seventy. 

When this test was first devised, iso-octane cost $300 per 
gallon rather too expensive to use in routine tests. So sec- 
ondary standards were made, of other compounds, which were 
treated against it; and they in turn were compared with the 
new gasoline. In fact, this is still done to some extent. Iso-octane 
now costs $9.00 per gallon, and heptane twenty-five dollars. 


However, chemists have produced fuels superior to iso-octane, 
one of which, called triptane, has the same number of carbon 
and hydrogen atoms as heptane the zero of the knocking scale. 
Though its price has been greatly reduced to a mere $40 from 
$3600 per gallon it is not likely to come into extensive use 
unless some cheap process of making it is found. According to 
Dr. Gustav Egloff, 1 triptane gives a power output 50 per cent 
better than iso-octane. 

The simplest hydrocarbon, methane, with one carbon atom, 
and ethane, with two, have octane ratings above 100, while 
propane, with three, has a 100 rating. The trouble with these, 
however, is that they are gases; and in order to keep them in 
liquid form for use in an engine they must be held under 
high pressure in heavy steel cylinders. Despite this disadvan- 
tage, their fine performance, and the fact that they are easily 
obtained from many oil wells and from natural gas, has resulted 
in their use in stationary engines, buses, trucks and even 
pleasure cars. They have been used in Germany, where filling 
stations were established to provide compressed gas on the 
road. Probably the heavy tanks needed to hold the liquefied gas 
will preclude its use in airplanes. 

But 100-octane gasoline can be made, and is being made. It 
has powered the airplanes of the United Nations, giving them 
a great advantage over those of the Axis Powers, which were 
unable to duplicate it. It enables engines of our fighting planes 
to operate with high-compression ratio and the greatest ef- 
ficiency. Dr. Egloff stated that on December 1, 1941, 100- 
octane gasoline was being produced in the United States at the 
rate of 168,000 gallons per day. This is 40,000 barrels, a figure 
which is being tripled. Every hour an average military plane 
will use 3.5 barrels, so a production of 120,000 barrels daily is 
enough to keep 35,000 planes in the air an hour each. 

What 100-octane gas will do for an airplane is shown by 
tests made by the Australian Institute of Automotive Engineers 
on a Koohoven (Dutch) FK59, a two-seater reconnaissance 

1 Director of research of Universal Oil Products Company. 



bomber with a Bristol-Mercury XV engine. It had to be mod- 
ernized to handle the powerful fuel, for an engine designed for 
87-octane gas, as this had been, will not run appreciably better 
on the 100-octane. That means, of course, that even if you 
could get such high-quality gas for your car, it would not be 
of any advantage to use it. But future models surely will have 
engines that will use such fuel, which then may be widely 
available; and their performance will be vastly improved by 
this war-dictated research. 

The Australian tests showed that the bomber with 100-octane 
gas had a maximum speed of 260 mph, compared with 236 on 
the old fuel; engine output was raised from 830 hp to 1050 hp 
and the absolute ceiling was increased from 32,800 to 36,700 
feet. A more complete summary of their findings is shown in 
the accompanying table. 

100 Octane vs. 87 Octane Gasoline in Airplane Performance 

Maximum speed at 2,750 rpm. 
Altitude for maximum speed 
Rate of climb at sea level 
Rate of climb at 6,500 feet 
Rate of climb at 19,500 feet 
Time of climb to 6,500 feet 
Time of climb to 26,000 feet 


Maximum output 
Maximum power height 

236 mph 
15,700 feet 
1,490 ft./min. 
1,630 ft./min. 
1,220 ft./min. 
4.2 min. 
19.4 min. 

260 mph 
17,300 ft. 
2,180 ft./min. 
2,360 ft./min. 
2,060 ft./min. 
2.9 min. 
12.2 min. 

830 hp. 

1,050 hp. 
15,580 ft. 

It is easy to describe the process by which these new gaso- 
lines are made synthetically as "just pushing molecules around"; 
and that gives some idea of what the chemist does, though it 
tells nothing about the years of work and research, in great 
laboratories, which have shown the way to do the pushing. 2 

2 In the original thermal cracking process, as introduced by Burton in 1913, 
heat and pressure were the main agents. In the last few years catalytic crack- 
ing processes have come into commercial use, employing those same "chemical 





D- U H 









(see page 66) 



The molecules are split into pieces, then rearranged. In many 
cases this rearrangement results in an entirely different type 
of molecule; one which, instead of having a chain structure, is 
built like a ring. In other words, the head of one of these chains 
is made to bite its tail and to hang on, like the mythical hoop- 
snake trying to swallow itself. Another process, called "hydro- 
forming," starts with naphtha, or gasolines of low-octane num- 
ber, and converts them into high-octane gasoline, having, pre- 
dominantly, the same ring structure. It does it, under the in- 
fluence of a catalyst, by re-forming the gasoline in the presence 
of hydrogen. Unlike hydrogenation, however, the hydrogen 
does not combine with the gasoline molecule rather, some of 
the hydrogen already there is removed to make other com- 

Still another process, related to these, takes the chain hydro- 
carbons, with at least six carbon atoms, and winds them into a 
ring like that of a chemical called benzene (which is one of the 
most important of chemical compounds) and its derivatives. 
The catalyst is an oxide of chromium, molybdenum, vanadium 
or titanium, in a base of alumina. This process has been of par- 
ticular importance because one of these benzene relatives is 
toluene, the basis of trinitrotoluene, or TNT, most used of war 
explosives. In the United States early in World War II, one 
commercial unit alone was capable of producing 30,000,000 
gallons of toluene annually, while, for the year 1942, a produc- 
tion of 70,000,000 gallons by such a process was projected. With 
another 30,000,000 from the coke industry, this made 100,000,- 
000 gallons, or five times the amount that the Army asked for 
in 1918, when toluene was all obtained from coal tar. 

The modern tendency in gasoline refining, it has been pointed 
out, is to use more and more of the catalytic reactions, because 
they can be so much more easily controlled, and are cheaper to 
operate, than the old ones with heat and pressure. The gasoline 

parsons" described in Chapter I. Several such methods are available, including 
the Houdry process, used by the Sun Oil Co., and those of the Standard Ofl 
of New Jersey and of the Universal Oil Products Company. 


thus made does not contain so many different hydrocarbon 
compounds as the old products. As Dr. Egloff puts it: 3 

The ideal would be a single hydrocarbon giving far greater power 
output than any of today. Combustion would then be controlled to 
an exactness impossible with today's gasolines, which contain hun- 
dreds of hydrocarbons each competing for the oxygen available. The 
results are not conducive to high efficiency. 

What this may mean for the future of air transportation is difficult 
to predict, but fuels of far greater anti-knock properties are possible, 
as well as more efficient engines and plane designs, tremendous speeds 
and airplanes carrying 1,000 or more passengers. 

And this is all a result of the fact that gasoline stopped being 
just a product extracted from a natural liquid, and became a 
synthetic product, custom-made by the chemist to fit his needs! 

As this tendency develops, compounds formerly, or even 
now, regarded as unsuitable for such molecule-juggling will be 
used. As a forecast of what the future may ultimately bring, 
we have the experiments of Dr. Ernst Berl, chemist of the Car- 
negie Institute of Technology in Pittsburgh, who said at an 
American Chemical Society meeting that "it is now possible 
to imitate nature and to carry out the production in a very 
short time, from carbohydrates, of bituminous coals which have 
exactly the same properties as natural bituminous coals." 

Carbohydrates are compounds such as starch and sugar, and 
cellulose, which forms the basis of wood fiber. They contain 
carbon, hydrogen and oxygen, the last two in the proportion of 
two to one, as in water. Oils can be made from them in the 
laboratory as well, Dr. Berl reported. 

In doing this, the chemist performs the same "miracle" that 
nature did over the ages, but does it in a matter of hours. By 
what Dr. Berl calls a "rather simple process" which involves 
heating the carbohydrate under high pressure with limestone, 
he accomplishes the change. If this can be perfected and com- 
mercialized, then perhaps farms, rather than mines and oil 
wells, will supply our fuel for tomorrow. 

3 Journal of Chemical Education. December, 1941: "Modern Motor Fuels," 
p. 582. 

IV. The Realm of Plastics 

Because modern synthetic plastics are so completely different 
from construction materials the world has previously known, it 
is rather difficult to find a concise definition which includes all 
members of the class, as it is conceived in the present day. Mr. 
Webster's "a substance capable of being molded or modeled, as 
clay or plaster," is hardly acceptable, because clay and plaster 
are not plastics in the modern sense. Since these are neither 
animal, vegetable nor mineral, they have been referred to as 
"the fourth kingdom." 

There are natural products that have some of the properties 
of plastics substances like shellac, which is produced by the 
lac insect of India; natural resins such as amber and rosin, and 
bitumen, which is a black, mineral pitch. But, although these 
are still widely used, the modern plastics industry has pro- 
duced a variety of synthetic materials that can be formed into 
any desired shape with pressure and heat. They can be made 
with a vast variety of properties, to meet specific needs. 

Heat acts upon them in one of two ways; and as a result, the 
field of* plastics is broken into two great divisions. One group is 
the "thermoplastics." These are softened when heated, and 
harden when cooled. But if they are again heated, they soften 
once more, and the process can be repeated time and time over. 
Members of the other class are "thermosetting." When the 
original material is softened by heat and formed to shape in a 
mold, it undergoes a chemical change; cross links are formed 
between the long molecules in which the atoms are strung to- 
gether. This makes a solid, permanently infusible and insoluble 
mass, unaffected by further application of heat unless at a tem- 
perature sufficient to burn the material. 

In addition to these two classes, plastics authorities some- 



times distinguish a third, "elastomers." These are plastics which 
can be softened with heat and molded to shapes desired. Some 
can be vulcanized. In this process, sulfur atoms are hooked on 
to the molecules, making them more solid and permanent, and 
the result is a substance like rubber. Though the elastomers 
might well be considered in a discussion of plastics, we shall 
leave them, on account of their growing importance, until 
later on. 

The modern plastics industry began in 1868, while General 
Grant was president, with a printer in Albany, N. Y. and a 
billiard ball! Up to then these balls were made of real ivory. 
But ivory from elephants' tusks was expensive; and the Albany 
printer, John Wesley Hyatt, discovered that a material resem- 
bling it could be made from cotton; a compound called cellu- 
lose. Like a great many useful substances, the molecules of 
cellulose are polymers, long chains of the same unit repeated 
again and again. This unit is a rather complicated arrangement 
of six carbon atoms, seven hydrogens, two oxygens and three 
sets of oxygen and hydrogen linked tightly together, called "hy- 
droxyls." These hydroxyl groups are characteristic of the chemi- 
cal compounds known as alcohols, and their importance lies in 
the fact that they can, in chemical reactions, easily be replaced 
with other groups, producing "esters." 

When cellulose is treated with sulfuric and nitric acids, ni- 
trate groups, each consisting of a nitrogen atom and three 
oxygen atoms, replace the hydroxyls. If this "nitration" process 
is carried to the point where some five-sixths of the hydroxyl 
groups are replaced, we have guncotton, an explosive. But if 
the process is halted when only 30 to 70 per cent of the groups 
have been changed, pyroxylin is obtained. Hyatt found that 
this could be mixed with camphor to make a thermoplastic, 
though he would hardly have recognized that name. He called 
it "Celluloid." 

First, billiard balls were molded of Celluloid. Then came 


plates for false teeth. In 1872 the Celluloid Corporation was 
founded, and thousands of uses were found for the material. It 
played a vital part in the development of amateur photography; 
and in the movies, too, when the company in 1890 perfected 
machines for making continuous transparent Celluloid films. 
Before that, George Eastman's first Kodaks had used paper 
film; but the new cellulose-nitrate film was a great improve- 
ment, ready for the experiments of C. Francis Jenkins, Thomas 
A. Edison and the other motion-picture pioneers of the nine- 

Because of its close relation to guncotton, it is hardlv sur- 
prising to find that Celluloid is highly inflammable. 1 Its in- 
flammability can be reduced with the addition of other com- 
pounds; but the Celluloid Corporation made a great step in 
1910 when they introduced cellulose acetate, which burns but 
slowly and has now superseded the nitrate for amateur motion- 
picture and X-ray film. (Professional motion-picture film, always 
handled with special precautions and by experienced persons, 
still employs cellulose nitrate.) With a host of other applica- 
tions, Celluloid is still important in the plastics field, and in the 
United States some 13,000,000 pounds are produced each year. 
That produced by Du Pont is known as Pyralin, while Amerith 
is another name for the cellulose nitrate of the Celluloid Cor- 
poration. Cellulose acetate also is now made by several manu- 
facturers. The form made by the Celluloid Corporation for the 
molding of various products is called Lumarith. The Eastman 
Kodak Company, using large quantities for film, likewise went 
into the plastics business and they produce it as Tenite. 2 

During the past century, in many products such as combs 
and telephone receivers, where plastics serve today, hard rub- 

1 Celluloid billiard balls sometimes exploded with a loud report. This caused 
a Colorado pool-room operator to complain. He said that he didn't mind, but 
it made his customers all pull out their guns. 

2 As we shall see in the next chapter, cellulose acetate can be spun into 
fibers to make a synthetic silklike yarn. One form, called Celanese, is produced 
by the Celanese Corporation. A similar fabric is Eastman Acetate rayon, prod- 
uct of the Tennessee Eastman Corporation, plastics subsidiary of the Eastman 
Kodak Company. 


ber, also known as vulcanite or ebonite, was used. The useful- 
ness of rubber lies largely in the fact that it is both thermoplastic 
and thermosetting. Pure rubber softens with heat, stiffens with 
cold a property which limited its use in the early days before 
the discovery of vulcanization. This is accomplished by adding 
sulfur. Soft rubber can be formed to any shape desired, such 
as that of an automobile tire; then sulfur is added to vulcanize 
it, and it sets into that shape. If only a little sulfur is used, the 
result is still soft and "rubbery." But if given all the sulfur that 
it can take, a hard mass results which is hard rubber. Black 
originally, it turns to a dirty green when exposed to sunlight 
and has a rather unpleasant odor. It absorbs oils and greases, 
and is brittle, so it must be made fairly thick to give the re- 
quired strength. Widely employed when there was nothing bet- 
ter, it is not surprising that modern plastics have made it prac- 
tically obsolete. 

The first serious challenge to the supremacy of Celluloid 
and hard rubber came about 1900, when Bakelite was invented 
by Dr. Leo H. Baekeland. Belgian by birth and American by 
adoption, he had already achieved fame as the inventor of 
"Velox." This was the photographic paper that, for the first time, 
made it unnecessary for photographers to wait for sunshine 
when making prints from their negatives. 

Baekeland took two compounds widely known as disinfec- 
tants. One was the gas, formaldehyde, generally used in a water 
solution called formalin. The other was carbolic acid or phenol. 
These react in the presence of a catalyst, and join together 
while a molecule of water splits off. At first they form mole- 
cules in long chains. If the reaction is stopped at this point, the 
material is a heat-softening plastic. The threadlike molecules, 
held together by physical forces which can be broken down 
with heat, can then slide against each other. As they cool, how- 
ever, the attractive forces again hold them together and the 


material becomes hard. This in general is the characteristic of 
any of the thermoplastics. 

The chief use of phenol-formaldehyde plastics in this form 
is to make an intermediate product which can be ground into 
powder for molding. The manufacturers sell such powder to 
other firms who do the molding. In this way the plastics in- 
dustry resembles the steel industry, where one group of manu- 
facturers make the material and supply it to others, who manu- 
facture it into useful products and structures. 

In the molding process, the powder is subjected both to heat 
and pressure, and it becomes a syrupy liquid, which is forced 
between the dies that mold it to shape. 3 Then the final stage of 
the reaction takes place. Additional chemical links are formed, 
this time crossing from one chain to another and making a three 
dimensional lattice, a resin, which cannot be broken down 
merely by the application of heat. Enormous molecules are thus 
built. Most people think of a molecule as something far below 
the limit of visibility of the microscope. However, the main 
pieces of your telephone handset, which is made of phenolic 
resin, are each, according to one point of view, single molecules, 
which you can easily see and handle. 

Resins of this kind, in the molded variety, are not available 
except in dark colors such as black or dark brown. When the 
catalyst which activates the combination of the phenol and 
formaldehyde is acid, the linkage takes place slowly and can 
be stopped where desired. But it is possible to prepare a liquid 
form which can be introduced into molds. Then the material, 
when heated, sets at a temperature well below the boiling point 
of water; and molded objects made from the cast phenolic 
resin are often brought to the right shape by being put through 
a machining process of sawing, turning, or threading. Such cast- 
ings can be made in a wide range of transparent or colored 

3 Usually finely ground wood, called "wood flour," is mixed with the molding 
powder. This acts as a filler, decreasing the cost, and also making the final 
article stronger. 


In addition to the familiar products in everyday use, many 
articles are made from these phenolic resins, both molded and 
cast, which play an important part in industry, but which the 
public seldom sees. Gears are an example. In 1908 the General 
Electric Company introduced a gear made of a pile of cotton 
sheets, cut to shape, and squeezed tightly between two steel 
plates by bolts running from one to the other. The cotton could 
soak up oil and keep the gear permanently lubricated. Since 
the use of such a gear avoided contact between metal and 
metal, it was very quiet. As an outgrowth of this there came a 
gear in which the compressed cotton is bonded by means of 
phenolic resin. This was produced under the name of Textolite. 
In recent years, the General Electric has made Textolite (and 
other plastics as well) for a variety of other and more general 
purposes and has become a leader in the industry. One novel use 
of Textolite is for women's high heels. 

Cast phenolic resins, because of their strength and resistance 
to water and many chemicals, have been used recently for such 
hard tasks as guiding, thousands of feet underground, a string 
of casing, weighing perhaps hundreds of tons, into a newly 
drilled oil well. And experiments have been made, quite suc- 
cessfully, in using the material for dies which, under pressures 
of as much as a ton to the square inch, shape aluminum parts for 
airplanes. Such dies, even after being used hundreds of times, 
are as good as new. 

One hard industrial use for bearings is in the necks of the 
rolls used in steel mills. These rolls perform the same function 
as the home rolling pin except that the steel-mill rolls squeeze 
thick blocks of steel into thin sheets, which is rather more 
strenuous. The bearings have to withstand pressures from 500 
pounds to as much as four tons to the square inch; and for- 
merly they were made of the customary bronze or Babbitt 
metal. Bearings of laminated phenolic plastic are now used, and 
they wear upwards of fifty times as long. In addition, they are 
more efficient in their operation, and so give power savings of 
from 15 to 60 per cent in operating the mill. 


Instead of phenol, a compound of carbon, oxygen, hydrogen 
and nitrogen, called urea, can be combined with formaldehyde 
to link the various atomic groups together to form the lattice 
structure of the big molecule. Such urea-formaldehyde plastics 
can be made transparent or brightly colored; they are odor- 
less and tasteless. Like their relatives from phenol, they set 
with heat. In finished form they are not as resistant to continu- 
ous heat, however; but in many uses this is not a serious draw- 
back. The trade-marked product "Beetle-ware" is made of urea- 

An important use of the formaldehyde resins is in making 
plywood. For some of the lighter planes flown in World War I, 
plywood was used, but in those days the thin wooden sheets of 
veneer were fastened together with animal or vegetable glue, 
which easily failed. Now, however, a solid and permanent bond 
may be made with either urea-formaldehyde or phenol-for- 
maldehyde resin. In the original method, plastic-impregnated 
sheets of tissue paper are interleaved between the layers of 
wood; then a pressure of about 200 pounds to the square inch, 
at a temperature of around 550 Fahrenheit, is applied for 
about ten minutes, forming a tight joint. 

Unlike the glued joints of older plywoods, such a bond is 
stronger than the wood itself. In more recently developed meth- 
ods, the plastic is spread on both sides of the wooden sheets, in 
solution in water or alcohol, and then dried. After that the 
sheets are pressed together. Heat usually is applied, and this 
is necessary for phenolic resins, though a method of cold press- 
ing, with the urea type, has been devised. The cold-press 
method is especially adapted to use in small shops where ex- 
pensive and special equipment for hot pressing is not available. 

It is even possible to apply heat to plywood assemblies by 
radio. This is basically similar to a device, used in the treatment 
of some diseases, by which very short radio waves are sent 
through the body and are absorbed by the tissues, heating 
them and killing certain germs that may be causing trouble. 
The plywood assembly can be bent, even into complicated 


shapes, between two dies which also act as electrodes. When 
the device is turned on, electrical waves between the dies gen- 
erate heating currents which flow through the plastic inter- 
layer, making the heat just where it is needed. Even if the 
assembly of plywood is very thick, the radio waves pass 
through, whereas, with direct heating, it might be hard to get 
the warmth into the center without having some bad effects 
on the outer layers. 

Rubber balloons are used for forming the complicated ply- 
wood fuselage and wing sections of airplanes, especiallv of the 
training types. These have been widely referred to as "plastic" 
airplanes, though that is hardly correct, since the plastic is 
only a small percentage of the total structure. Thin wooden 
veneers, with the interleaved plastic sheets, are laid over a 
form of the proper shape; then the rubber bag is placed on top 
and inflated with steam, giving at once heat and moderate 
pressure enough, with the materials used, to make a tight 
bond. (The tightest fits are made with the phenols, but they 
require somewhat higher temperatures than urea plastics.) 
Plastic-bonded plywood has even been used by the British 
for first-line fighting planes. The tiny Navy patrol torpedo boats, 
making up what is popularly called the "mosquito fleet," also 
are made largely of the same material, which successfully with- 
stands even the buffeting encountered at speeds of 70 miles per 

In World War I, some of the military planes were fitted with 
sheets of cellulose nitrate, the only transparent plastic then 
available, for small unbreakable windows. But in addition to 
its inflammability, cellulose nitrate is unstable when exposed 
to sunlight; and with age it also tends to shrink and crack. In 
great contrast are the transparent plastic noses of bombing 
planes today ( like that shown in the Frontispiece ) , or the hoods 
for the cockpits of fighters, which sometimes are made in large- 
single pieces, precisely formed to shape, permanently clear and 
much lighter in weight than glass. These are generally of methyl 


methacrylate, a plastic which goes back to the researches of a 
Darmstadt chemist, Dr. Otto Rohm. 4 

The basic synthetic process for making acrylic resins, which 
are produced from petroleum, coal, air and water, is fairly 
complicated; and methyl methacrylate is the most expensive of 
the plastics. However, its beautiful clarity and resistance to 
weathering make it supreme for use in airplanes. It is thermo- 
plastic. It softens at about the temperature of boiling water. 
The sheets can then be bent down over forms and held until 
cool. Under pressure it will flow somewhat, even when cold; 
but if the parts are so mounted that they are not under pressure, 
there will be no distortion. 

Because of the clarity of the acrylic resins they can even be 
used for lenses, both for magnifying purposes and for eye- 
glasses, where they have the great advantage of being unbreak- 
able. They are so transparent that light will pass through a rod 
of such a resin like water through a pipe that is, light hits 
the surface always at such a low angle that it is totally reflected. 
For this reason the material is used to pipe light into dark 
places; the mouth of a patient seated in a dental chair, for ex- 
ample. This same quality makes it suitable for signs, which can 
thus be illuminated from the edge. If the lettering is engraved 
or stamped into the surface, it shows up in luminous words. 

Often manufacturers want to show the operation of some 
piece of equipment; a telephone, a water meter, an electric 
razor. Then the casing may well be made of an acrylic resin, 
and it permits a beautiful demonstration. One of the outstand- 
ing examples of this kind was a Chrysler automobile body 
which Rohm and Haas made a few years ago out of Plexiglas. 

However, the articles do not need to be transparent. Since 
the material itself is completely colorless, pigments can be in- 
troduced as desired, to give the most delicate shades. False 

4 About 1900. In 1931 acrylic resins became available in the United States 
in the form of sheets, and in 1937 as a moldable plastic. Two forms in which 
it is widely used are Lucite, a product of Du Pont, and Plexiglas, made by 
Rohm and Haas. Acryloid and Crystalite are other names. 


teeth, naturally tinted, have been made of these resins, and so 
have dental plates. In radio sets and automobile instruments, 
acrylic resins are used for indicating panels, with the numerals 
stamped in and colored. These panels also lend themselves to 
edge illumination. 

In the automobiles of two decades or more ago, windshields 
were a source of great danger in a collision. The flying glass 
often produced severe injuries where otherwise the passengers 
might only have received a shaking. Then came safetv glass, 
a sandwich made up of two sheets of glass as the bread and a 
sheet of cellulose nitrate or cellulose acetate as the ham. This 
was pressed together and heated, and the plastic layer held 
the glass tightly. Then, when the glass was broken, the wind- 
shield remained rigid, and the sharp fragments were not thrown 

A better material was found among the vinyl resins, a class 
of plastics with applications as diverse as phonograph records, 
electrical insulation, women's hats, men's suspenders, and lin- 
ing for beer cans. The particular form used for safety glass is a 
combination of vinyl resin with a material called butyralde- 
hyde. 5 It comes in sheets, cross-ribbed with slight depressions 
so that they will not stick to each other when piled. Pressed be- 
tween glass and heated, it flattens out and becomes entirely 
transparent. A windshield so made will yield when you hit it, 
and the result may be only a bruise instead of a fracture. 

Vinyl alcohol has been known for more than a century. It 
consists of carbon, hydrogen and oxygen, the characteristic 
grouping being an arrangement of a carbon with one hydrogen 
atom, attached to another carbon with two hydrogen atoms. 
Two chemical "bonds" hold these two groups together; but 
only one is needed, so the other is available for linking the 
groups together in forming the polymer. In the alcohol, the 

8 Butacite is the name of this material as made by Du Pont, and Butvar as 
made by another manufacturer, the Shawinigan Products Corporation. 


carbon to which the single hydrogen is attached is also linked 
to the characteristic hydroxyl (hydrogen and oxygen) group. 
But this can be replaced with chlorine to make vinyl chloride, 
or with an arrangement of three hydrogens, two carbons and 
two hydrogens ( obtained from acetic acid ) to make vinyl ace- 
tate. The chloride makes a rubber like material that we shall 
meet later as Koroseal, produced by the B. F. Goodrich Com- 
pany, and as Flamenol, the flame-proof G-E insulation for elec- 
trical wires. 

The chief form in which the material is used, however, is a 
combination of the acetate and the chloride; what is called a 
co-polymer. Here the chain molecules contain links of both 
kinds. They may alternate, or most of the links may be made of 
one form. At the present time these plastics usually contain 
from 80 to 95 per cent of the chloride. 

Like some of the other plastics, this material, known as 
"Vinylite series V" and, in fibers, as Vinyon, both products of 
the Carbide and Carbon Chemicals Corporation, has to be 
mixed with a plasticizer for use. It can be molded, with pres- 
sures from 1200 pounds to a ton per square inch and tempera- 
tures of 250 to 290 Fahrenheit. Or it can be extruded. Then 
the material, softened by heat and pressure, is squeezed through 
an opening like toothpaste from a tube. The plastic solidifies 
and takes a cross-sectional shape corresponding to that of the 
opening. In such a way, long ribbons or rods may be made. 
Essentially the same thing is done in making this plastic into 
fibers for fabrics. Then the openings, very small, are called 
"spinnerets." 6 

Alkyd resins, still another class, are made up of large and 
quite complicated molecules. Used largely for lacquers in fin- 
ishing automobiles (in the form, for instance, of Dulux, made 

6 War uses of late have taken up most of the production of vinyl resins. The 
fact that they will burn when held in a flame, but go out as soon as removed, 
is most important. This quality results from the presence of chlorin. The basic raw 
materials are natural gas, salt water, coal and air, which seem plentiful enough; 
but here again electric power is needed in large quantities, particularly in 
making acetylene, which enters into the process. 


by Du Pont), their civilian applications have lately given way 
to war ones. With high gloss, excellent resistance to sunlight, 
the ability to stick tightly to metal and to retain their new ap- 
pearance for a long time, they are now mainly used as a finish 
for the superstructure of naval vessels. 

One of the most important of chemical compounds is benzol 
or benzene (not benzine, which is really a form of gasoline). 
It consists of a six-sided arrangement of six carbon atoms, to 
each of which a hydrogen is attached. This is often referred to 
as the "benzene ring," and is represented as a hexagon, which 
appears in the official insignia of the Chemical Warfare Service 
of the United States Army. Since any, or all, of the hydrogen 
atoms in the benzene ring may be replaced by other atoms or 
atomic groups, it forms the basis of an enormous number of 
compounds. If the top hydrogen is replaced by our friend the 
vinyl group (carbon and hydrogen, then carbon and two hy- 
drogens) the result is vinylbenzene, otherwise known as sty- 
rene, named after a plant from which it was originally obtained. 

Petroleum and coal are now the raw materials from which 
styrene is made. The first step is to make ethyl chloride and 
benzene, which are combined into ethylbenzene. Then this is 
"cracked" to produce styrene, which can be polymerized to 
polystyrene. Thus we have the plastic marketed as Styron by 
the Dow Chemical Company, Lustron by the Monsanto Chem- 
ical Company, and Bakelite Polystyrene by the Bakelite Cor- 
poration. It comes in the form of a molding powder, which can 
be softened by heat, then squirted into an injection press, where 
it is formed by pressure into the shape desired. Crystal clear 
ordinarily, it can be colored as desired. 

The most remarkable property of polystyrene, however, is 
its extreme resistance to chemical attack. Even hydrofluoric 
acid, which dissolves glass, will not affect it, so polystyrene bot- 
tles are now used as containers for the acid. Polystyrene ab- 
sorbs water so slightly that the most delicate measures are re- 
quired to detect the absorption at all. Also, it is an excellent 


electrical insulator, a sheet a thousandth of an inch in thickness 
being able to resist up to 3000 volts. 

In describing the rapid development of plastics, it is im- 
possible in a single chapter to cover them all. There are many 
other types plastics made from milk casein, and from the soy 
bean, for example which have important uses. With the in- 
tervention of the war, it is fortunate that plastics have been 
developed so extensively in recent years making it possible, 
for instance, from a material formerly employed for men's gar- 
ters, to fashion clothing that protects against deadly poison gas. 

V. Chemical Clothes 

Thanks to the chemist, the coming of war with Japan, with 
its complete stoppage of silk imports, did not have the effect it 
would have had at an earlier time. Out of the laboratories had 
come products not only equaling that of the silkworm but ac- 
tually surpassing it. Large-scale production was forced on our 
industries and in peacetime they will now be in a position to 
continue to supply our needs. Like so many of our most mod- 
ern scientific developments, however, the idea of synthetic 
fibers is not new. Robert Hooke, great English scientist of the 
seventeenth century and one of the first users of the microscope, 
studied many natural fibers with his powerful instrument, and 
in 1664 suggested that they might be made artificially. In 1734 
the Frenchman, R. A. Reaumur, asked as a result of his re- 
searches on silkworms and spiders: "Silk is only a liquid gum 
which has been dried; could we not make silk ourselves with 
gums and resins?" 

But it was 106 years until Reaumur's question was answered 
when a Manchester silk manufacturer, named Schwabe, tried 
making resins of such compounds as gelatin, egg albumen and 
a species of moss, then spinning them through fine holes into 
filaments. This device was the forerunner of the modern spin- 
nerets for rayon, but the fibers were not satisfactory. 

Then came Count Hilaire de Chardonnet, in France. He had 
been a pupil of Pasteur when that great man was studying the 
silkworm diseases whence, it is supposed, came his interest in 
textile fibers. He made the first commercial synthetic fiber in 
1884, and his results, when shown at the Paris Exposition in 
1889, created a great sensation. First Chardonnet used pulp 
from the mulberry tree; then wood pulp and cotton cellulose 
were employed. The cellulose was treated with nitric acid 



(making what was practically guncotton) this nitrocellulose 
was dissolved in alcohol and ether, and then spun through small 
holes. The method is still used occasionally, but it has been 
almost entirely replaced by others. 

The viscose process, which has been and still is widely used, 
dates from 1892 when two English chemists, Cross and Bevan, 
found that certain compounds of cellulose could be made which 
were soluble in water. Because of the difficulty in handling the 
wet filaments, a centrifugal method of spinning was developed. 
Less expensive than Chardonnet's method, or still another the 
cuprammonium process that had meanwhile been introduced 
it had rapid development. 

All these three methods have one point in common the 
product is simply cellulose, the same as at the start, but re- 
generated after some chemical juggling. This, however, is not 
true in the case of the fiber now known as Celanese. It starts 
out with cellulose acetate, used for non-inflammable motion- 
picture film, which has largely superseded the old, dangerous 
Celluloid or cellulose nitrate. 

Before the First World War two Swiss chemists, brothers, 
Drs. Henry and Camille Dreyfus, started producing cellulose 
nitrate. During the war they established a plant near London 
to make it for airplane "dope." (Planes of that generation had 
fabric wings, and these were "doped" to render them less in- 
flammable.) Then Dr. Camille Dreyfus came to the United 
States, at the request of our government, to establish a similar 
plant. This was started at Cumberland, Md., but the war was 
over before it was completed. As the Dreyfus brothers had 
previously done some work on textile fibers, those experiments 
were resumed; and the result was Celanese. 1 The fibers are 
made by dissolving cellulose acetate in acetone, from which it 
is solidified, in thread form, in warm water or air. 

A high luster was a characteristic of the first rayons, one to 

1 It first appeared in 1925, a year in which something over 51,000,000 pounds 
of rayon yarns of all types were used, only 1,620,000 pounds of which were 
Celanese. Fifteen years later, however, the total had risen to more than 390,- 
000,000 pounds, about a third of which were acetate rayons. 


which many people objected; so a process for removing the 
luster was devised. The removal, though, was not permanent, 
so it was an improvement when non-lustrous yarns were later 
produced. These yarns differ considerably in the amount of 
moisture they contain. Water causes the fibers to swell and 
to lose strength. However, they resume their strength when 
dry again. 

It is interesting to see how, even before World War II, the 
use of rayon had replaced Japanese silk. In 1929 the United 
States consumed 59,100,000 pounds of raw silk for weaving and 
48,500,000 pounds of rayon for the same purpose. But in 1939 
the consumption of raw silk had dropped to 8,900,000 pounds, 
whereas that of rayon had increased to 285,700,000 pounds. So, 
even before war cut off our silk supply, we were becoming 
largely independent of it, anyhow, by using straw, wood pulp, 
or cotton as the original source of the cellulose raw material. 


As a by-product of the rayon industry has come a very popu- 
lar type of wrapping material, known as Cellophane when pro- 
duced by the Du Pont Company, Kodapak when the Eastman 
Kodak Company makes it and many other names. Cellophane 
is made by the viscose process, but, instead of being spun 
through spinnerets into threads, it is formed into sheets through 
a narrow slit. Often, too, these sheets are slit into fibers as nar- 
row as a hundredth of an inch for use in textiles. 

The casein from skimmed milk has been employed, especially 
in Italy, to make a synthetic fiber called lanital. In the United 
States it has been produced under the name of Aralac, and 
mixed with rabbit fur in the manufacture of felt hats. The 
casein fibers have less elasticity and strength than wool, which 
they resemble more than silk. They also stretch more than wool, 
particularly when wet. On the credit side, however, they are 
non-shrinkable, and are not attacked by insects. 

The Ford Motor Company has been responsible for experi- 


ments with a fiber made from soy beans. This, the "honorable 
bean" of China, can be grown easily in the southern parts of the 
United States. Many researches have been made into its use 
as a base for paints and plastics, so that much of the fiber, as 
will be seen, may be available as a by-product. The bean is 
crushed, the oil extracted. Then the meal is put through a salt 
solution which extracts the protein, and the residue is spun 
through spinnerets into a bath which makes the solution coagu- 
late. The fiber has 80 per cent of the durability of wool. 

There are also fibers made of synthetic resins, essentially the 
same as some of the plastics. One, Vinyon, is made up of links 
of molecules of great length, consisting of alternate links of 
compounds called vinyl chloride and vinyl acetate. The process 
of making the fiber from either coal or natural gas, and salt, 
water and air, was developed by the Carbide and Carbon 
Chemical Corporation, and the product is made by the Ameri- 
can Viscose Corporation. As Vinyon is unaffected by molds or 
fungi, and is as strong when wet as when dry, it has many 
possibilities, though its use in clothing is limited by the fact 
that it begins to shrink at temperatures of 150 Fahrenheit, 
well below boiling. At about 175 Fahrenheit, too, the fibers 
tend to stick together, and this of course makes it difficult to 
iron. One novel use has been found for Vinyon, however as 
fishnets. Along the Florida coast they caught twice as many 
fish as tar-impregnated cotton nets, and were as good as new 
after six months' use. 

Striking for many reasons has been the development of 
Nylon by Du Pont, under the direction of Dr. Wallace H. Ca- 
rothers, whose brilliant career was ended by death just when his 
achievements were showing fruit. In 1927 the company's chem- 
ical director, Dr. C. M. A. Stine, decided to set up as an im- 
portant activity of his department fundamental research (as 
distinct from the applied research then occupying the various 
research divisions of the manufacturing departments), which 


would be devoted to filling in gaps of knowledge. It was to 
explore new realms of chemistry in order to find facts that might 
perhaps be of future value to the company. 

Dr. Carothers, with two years' experience behind him as an 
instructor of chemistry at Harvard, was brought to Wilmington, 
where he chose to work on the project of making big molecules 
out of little ones the process technically called "polymeriza- 
tion" by condensation from vapors. In connection with this 
he studied the structure of the molecules of long chains of 
atoms, a field which had been slightly explored up to then. A 
device called the "molecular still" made it possible to obtain 
longer molecules than any that had been made before. These 
polymers, which are formed of regularly recurring units, have 
been compared to a chain of paper clips hooked together. 

Finally it was found that some of these products were solids, 
tough and opaque, which could be melted to thick transparent 
liquids. By dipping a rod into this molasseslike fluid and pulling 
it out again, threads are formed. But the most important thing 
the researchers noticed was that, even after these threads had 
cooled, it was possible to pull them to several times their orig- 
inal length whereupon they became much stronger and more 
elastic. They could be tied into hard knots, a process in which 
the original filaments were easily broken. It was also found that 
these cold-drawn fibers, unlike most natural fibers and rayon 
as well, did not lose strength when they were wet. 

What happened was revealed by X-ray studies of the ar- 
rangement of the molecules. They are really crystals; that is, 
the atoms are arranged in definite lattice formations; but in 
the original threads these molecules are helter-skelter. The 
cold-drawing, in stretching them and reducing their diameters, 
rearranges these crystals into parallel positions in which they 
are much closer together. Intermolecular forces then help to 
keep them so. 

As a modification of the process of making the fibers from 
the melted material, it was discovered later that the compound 
could be dissolved in chloroform, then spun in air through 


spinnerets, as with the cellulose-acetate rayon. Like the fibers 
pulled from the molten bath, they too could be pulled into the 
strong condition when cold. 

Up to this point, the work had been mainly of theoretical in- 
terest, for the compounds melted at temperatures too low to 
permit their commercial use, and they dissolved too easily. 
However, one of the earlier compounds that Carothers had 
studied belonged to a class known as "poly amides." These he 
had put aside as being too difficult to handle; and, at this point, 
it seemed as if there was little hope of securing something com- 
mercially successful from his researches. For a number of 
months they were actually discontinued. 

But then Carothers went back to his earlier problems; and 
he decided that the polyamides were best after all. Using the 
molecular still he prepared a compound which had a melting 
point of 383 Fahrenheit, a satisfactory figure. And when it was 
cold drawn, it equaled silk both in strength and pliability. This 
indicated that from the supposedly useless researches there 
might indeed emerge a useful material. Then came the search 
for the best polyamide, and on the last day of February in 1935 
Carothers found the one that proved best. Chemically known 
by the long name of "polyhexamethylene adipamide," it was 
generally referred to as "66," figures which indicated the 
number of carbon atoms in the different parts. When it was 
decided that this should be used, a special effort was made, 
as W. S. Carpenter, Jr., president of the company, put it, to 
reduce to a minimum "the time between the test tube and the 
counter." About 230 chemists and chemical engineers, some 
from other departments, such as the one which had been mak- 
ing rayon, were transferred to wage a blitz campaign to put it 
into production. It was christened "Nylon." 

Many problems were involved: the two raw materials, 
hexamethylenediamine and adipic acid, had to be produced in 
quantity. The former had been a laboratory curiosity, and the 
latter was produced commercially in Germany alone. But a 
successful method of making these from bituminous coal, water 


and air was devised whereby, after the chemicals are mixed 
and combined under heat and pressure, the melted Nylon comes 
out as a ribbon to form on a chilled metal roller. The ribbon 
then is cut into chips, a convenient form in which to store it. 
When the fibers are to be made, these chips are melted again 
over a heated grid and blanketed with an inert gas; for other- 
wise oxygen from the air might cause undesirable effects. The 
liquid Nylon is pumped through spinnerets; the threads harden 
as soon as they strike the air, and are wound up on spools, which 
handle about half a mile of thread per minute. Then they are 
stretched approximately four times to give them their final 
form, which has great strength and elasticity. 

From this point on, the threads are handled like any other 
textile. By October 27, 1938, hosiery manufacturers had tried 
the new yarn, some details of use which had produced unsatis- 
factory results in the first tests had been overcome, and it was 
announced that a large-scale plant was to be built at Seaford, 
Delaware. It started operation at the beginning of 1940 with a 
production capacity of 8,000,000 pounds of Nylon per year. 
This was less than five years after the "66" material had been 
invented truly a remarkable achievement and during 1942 
a second plant, with equal capacity, was scheduled for full pro- 
duction. Plans were quickly made for increasing this even fur- 
ther, since the product has certain important war uses notably, 
as parachutes. 

Nylon is not a single material but a family of materials. So 
far, the form used for hosiery has received most attention; but 
it can also be used for tooth-brush bristles and tennis-racket 
strings, or, by modifying it chemically, it may be given some- 
what different characteristics. Although it does not equal silk 
or wool in resilience (that is, in the ability to recover quickly 
from wrinkling), "Nylon yarn is the first truly synthetic fiber, 
and has a closer similarity in both constitution and properties 
to silk than has any other fiber," said Dr. Elmer K. Bolton, 
Du Pont chemical director since 1930, in a lecture. "For the first 
time the age-old problem of making a material closely re- 


sembling silk appears to be solved. It has the appearance and 
luster of silk, although the degree of luster can be modified as 
desired. It possesses, moreover, the advantage of having greater 
uniformity than silk and, in addition, filaments of any desired 
size may be spun." 

It is Nylon's strength when pulled that is one of its most 
important qualities. Even when wet it equals dry silk in tensile 
strength, while wet silk is considerably weaker. Its tensile 
strength exceeds that of wool, silk, rayon or cotton. In elasticity, 
too, it has remarkable properties, since it can be stretched 20 
per cent before it will break. Again, it completely recovers after 
stretching, whereas silk or viscose rayon would remain partly 
stretched. Its melting point, about 480 Fahrenheit, is above 
that normally used in ironing, and when in a flame it does not 
blaze, but melts. It is not subject to mold or mildew, nor to 
attack of moths. Truly, the fundamental research that Dr. 
Carothers started in 1927 has had remarkable results! 

A new fabric development that is one of the many promising 
products for a post-war world has been announced by the B. F. 
Goodrich Company. Now stockings can be made that will not 
run even if a nail is poked through them. Food packed in bags 
sealed with a hot iron, and colorful draperies which are so 
waterproof that they can be cleaned by squirting a hose on 
them, are other possibilities. Koroseal, which will be described 
in the next chapter, is the basis of this advance. Though the 
manufacturers point out that, strictly speaking, it is not one of 
the synthetic rubbers, it is related to them, and is often classified 
under that head. 

The runless stockings are made in two ways. In one, fibers 
of the usual sort are coated with Koroseal. Another uses fibers of 
Koroseal mixed with silk. Probably either natural silk or one of 
its synthetic forms would work just as well. 

Not only have synthetic materials replaced natural yarns 


used as fabrics they have also started to take the place of 
animal hides, or leather. The material used for such purposes 
is practically the same as Vinyon, but made up in sheet form 
instead of in fibers. Men's belts, suspenders, garters and wrist 
watch straps, women's shoes, aprons and braiding for hats 
these are a few of the forms in which these vinyl plastics 2 have 
been used for wearing apparel. All these can be made trans- 
parent, a novel quality in such articles; and so that feature has 
been emphasized, though it is not essential. Indeed, the same 
property of softening at a relatively low temperature, which 
imposes some limitations on the use of vinyon, makes it possible 
to mold vinyl plastic and to form the surface into any crinkly 
or other form that may be desired; and by adding coloring 
matter it can be made in any color, or entirely opaque. 

Such material is non-inflammable, resists most chemicals, and 
absorbs little water, even after long soaking. It is flexible, but 
does not snap back immediately, like rubber. Rather does it 
have a lazy return, gradually resuming its original size and 
shape. When used for shoes, the material generally is perforated 
to allow ventilation and relieve the overheating that might 
occur because of its moistureproof quality. But because of the 
elastic properties, perhaps fewer shoe sizes would be needed if 
it came into wide use, since the uppers can give with move- 
ments of the foot. In cleaning the vinyl plastics a damp cloth 
suffices. Women's shoes have been made from them, and doubt- 
less men's shoes will be along in the future. 

This use of plastics for clothing is not as new as one might 
imagine. When Celluloid, the first of the modern plastics, was 
introduced in 1868, one of its early uses was in grandpa's 
Celluloid collar. This never wilted, and when soiled it could be 
cleaned with a damp sponge; but a "No Smoking" sign should 
really be worn along with it. Celluloid collars easily caught fire; 
and singed whiskers, or worse, resulted. Vinyl plastics have not 
yet been made into collars, but one use closely related is for a 
"dickey," or stiff shirt front, for wear with dress clothes or by 

2 Made by Carbide and Carbon Chemicals Corporation. 


waiters. It can be made perfectly white and molded, with heat, 
to any kind of surface that is desired, simulating a fabric. 

For women's costume jewelry, too, these synthetic materials 
have proved a boon, especially since the supply of Czecho- 
slovakian glass was cut off in the early days of the war. Poly- 
styrene is one; methyl methacrylate, known as Lucite or 
Plexiglas in two of its forms, is another. They have a high index 
of refraction; that is, light is bent considerably as it passes into 
them or out again; and the result is a sparkle like that of 
natural minerals. 

Not only has chemical science shown how to make synthetic 
fibers it has also revealed ways in which natural fibers may be 
changed and improved. For example, wool is in some respects 
an ideal material for clothing. But it has disadvantages, too. It 
cannot be washed without weakening, and one of its greatest 
enemies is the moth. 

Now researches made at the Textile Foundation in the 
National Bureau of Standards have resulted in wool which gives 
moths indigestion, and which can be washed as readilv as 
cotton. The process, known as "alkylation," has been developed 
under the direction of Dr. Milton Harris, and is similar in some 
of its effects to the vulcanization of rubber. It replaces weak 
connections between the sections of the long and complicated 
wool molecules with stronger and more resistant bonds. 

The wool molecules consist of a chain of twenty or thirty 
different kinds of chemical substances, called amino acids. 
Connections between parallel chains are made by pairs of atoms 
of sulfur, and the number of these cross links determines the 
desirable properties of the fiber, Dr. Harris has found. 

A chemical called thioglycollic acid, which used to cost $17 
per pound but is now available at well under a dollar, is able to 
pick out and sever the double sulfur bonds without affecting 
the long chains themselves. Fibers so treated are much weaker 
than the original wool, but exposing them to oxygen regenerates 


the sulfur bonds, and the strength returns. However, the 
treated fibers may also be relinked with another group, known 
as an "alkyl residue/' This consists of one carbon atom and two 
hydrogen atoms. Such "alkylated" wool is stronger than the 
original; it resists moths and mildew, and can be washed with 
soap and water without weakening. 

Dr. Harris and his colleagues have found that moths thrive 
on ordinary wool because their intestinal fluids are extremely 
alkaline. Ordinary wool is highly soluble in alkaline solution 
because the double sulfur linkages are affected. On the other 
hand, the links made of the alkyl residues are very slightly 
soluble in alkalis. Thus moths may nibble the edges of fabrics 
made of alkylated fibers; but they do not eat holes clear 
through, for that would give them indigestion. 

VI. Rubber from Tree and Test Tube 

Like tobacco, rubber was an American contribution to the 
world. Columbus, on his second voyage, found the Indians 
playing games with a heavy black ball, which rebounded with 
such vigor that it seemed to be alive. The ball, he was told, was 
made of a gum obtained from a tree. But the world had to wait 
three centuries, until about 1800, before a commercial use was 
found for the material. It could be used, men learned, to rub 
out pencil marks so it was called "rubber." In the United 
States that name has stuck, replacing the old name, "caout- 
chouc," which more or less accurately reproduced what the 
Indians called it. 

Early nineteenth-century scientists began to wonder what 
the compound was chemically; and Michael Faraday, better 
known for his discovery of the fundamental laws which made 
electrical generators possible, supplied a partial answer in 1826. 
He showed that it consists of carbon and hydrogen in the pro- 
portion of five atoms of carbon to eight atoms of hydrogen 
that is, its formula is C 5 H 8 . 

In those days rubber was not strong enough to be of much 
use. Raincoats had been made of it, but when they were ex- 
posed to cold weather they became stiff enough to stand by 
themselves. Heat, on the other hand, softened the material. 

The discovery of the proper treatment came in the tradi- 
tionally accidental style of the old-time kitchen inventor. In 
1839 Charles Goodyear, in New Haven, was working on the 
problem of giving rubber the strength and resistance which it 
lacked. He had tried mixing sulfur with crude rubber, but with- 
out much success, though this was a step in the right direction. 
Accidentally he spilled some of the sulfur-rubber mixture on 
the kitchen stove, a tough mass formed and this proved to be 



the answer. Thus the process of hot vulcanization of rubber 
was invented, and the modern era of the usefulness of rubber 

Then, and well into the twentieth century, rubber came from 
trees which grew in Central and South America, especially in 
Brazil. The most useful tree for the purpose was and is one 
called by the scientific name Hevea brasiliensis, the latter, the 
specific, part of the name denoting its country of origin. There 
the trees grew wild, natives tapped them, and from the latex 
which exuded they prepared the crude rubber. 

As early as 1873 a start was made, under English auspices, 
in establishing rubber plantations in other parts of the tropics 
where the necessary conditions of a heavy and well-distributed 
rainfall and average temperatures of from 70 to 90 Fahrenheit 
prevailed. In 1900, however, only four tons of plantation rubber 
were produced, as compared with 26,750 tons gathered from 
the forests of Brazil. In 1912, as the use of rubber for automobile 
tires began to assume importance, Brazilian production was 
42,410 tons, still surpassing the plantation production, mostly in 
Eastern lands, of 28,518 tons. The following year plantation 
production forged ahead, and it has remained in the lead ever 
since. During recent years the Brazilian contribution to the 
total production of well over a million tons, more than half of 
which was used in the United States, has been insignificant. But 
still the Brazilian tree, transplanted by botanical experts to new 
homes, was the main source. 

Conditions being right, these trees develop in from seven to 
ten years. Then, with trunks about six inches in diameter, they 
can be tapped. When properly done, this process can be re- 
peated every few days for many years. While some trees yield 
only four to five pounds of latex a year, others give as much 
as thirty pounds. Naturally, the scientists have tried to breed 
trees which give the maximum yield. 

The labor situation in the East Indies has been favorable 
for rubber growing, with a large native population of Malays 
who are willing to work under tropical conditions at low wages. 


In most of the American regions where soil and climatic con- 
ditions are right, the labor is lacking, for there is only a sparse 
population of native Indians in the jungles, and they have no 
desire to do such work. In the more settled regions, people of 
mixed blood, either Latin-Negro or Latin-Indian, want higher 
wages. Perhaps this is not an insuperable problem, however, for 
improved methods of collecting and processing the latex, in 
addition to the breeding of trees with higher yields, may make 
possible the production of natural rubber economically, even 
though labor does cost more. 

Even before the war, the potential danger was recognized of 
having our supply of such a vital material as rubber come from 
such a great distance over seas that might be controlled by an 
enemy. Henry Ford, for example, sponsored a plantation 
venture in the valley of the Amazon. Afterwards, with the 
rubber supplies from the East actually cut off and the Indies 
plantations themselves in enemy hands, the situation was made 
clear to all. Over the last few years, a stock pile of rubber had 
been accumulated, but this was needed entirely for the 
American war machine. Now, finally, rubber trees are being 
planted in Central and South America. The rubber tree has 
returned to its native home; but since no appreciable yield can 
be obtained from a tree for five years at least, this does not 
afford an immediate answer to the rubber shortage. 

Perhaps other plants can supply part of the deficiency. In 
theory, at least, protein molecules from soy beans can be re- 
arranged to form chainlike molecules similar to rubber. A shrub 
known as rabbit brush, which grows to a height of as much as 
ten to twelve feet as a weed in waste lands of the West, is 
another possible source, to which Dr. T. Harper Goodspeed, of 
the University of California, has called attention. At least 25,000 
tons of rubber could be obtained from its roots and stems, he 
believes, though it would not be as good as rubber from the 
Hevea tree, and would be more expensive to prepare. But the 
most promising source of natural rubber, other than Hevea, is 
the Mexican guayule shrub. This has been grown for thirty-five 


years by the International Rubber Company in Texas, Arizona 
and the Salinas Valley in California. 

Guayule (pronounced why-t/ow-lee ) planted in the spring 
can be harvested to some extent the following autumn. Densely 
planted, this yields about 1100 pounds of rubber per acre after 
a year. But if the plants are allowed to grow for four years or 
more, the yield is many times increased, and the cost is reduced. 
At the end of 1941 it sold for about 16 cents a pound, and this 
might be lowered to ten cents. East-Indian rubber sold at that 
time for about 22 cents; so guayule seems definitely promising. 


Beginning with indigo, chemistry has succeeded in synthe- 
sizing many natural products, often so successfully as to replace 
nature's work. These triumphs usually come in three stages. 
First, the exact chemical composition and structure of the 
original would be determined by chemical research. Then 
methods were developed to duplicate it from cheap and avail- 
able raw materials. After this would come commercial pro- 
duction on a large enough scale and at low enough cost to 
permit it to compete with, and perhaps to replace, the natural 
product, as happened with indigo, and, in more recent times, 
with the vitamins. For the production of the chemist is 
chemically identical with the original, not an improvement its 
advantage being that it can be made more cheaply and purer. 

Such was, at first, the pattern followed by the rubber re- 
searchers. Faraday had shown the basic formula of rubber to be 
C 5 H 8 . In 1860 an Englishman, Greville Williams, broke up 
rubber with heat and obtained a chemical called isoprene. This 
molecule contains four carbon atoms and five hydrogen atoms 
in various combinations in a row. Branching off to the side, and 
attached to one of the carbon atoms, is a "methyl group" made 
of a carbon combined with three hydrogens. This totals five 
carbons and eight hydrogens, in accordance with Faraday's 


However, this is not rubber. Isoprene is the "monomer," one 
of the links in the chainlike molecule, or "polymer ," of which it 
is made. Hundreds, or even thousands, of such links are joined 
together to form the long molecule of rubber. This structure 
was suggested first by the Frenchman Gustave Bouchardat 
who, in 1879, actually made a product remotely resembling 
rubber, with isoprene as a basis. 

This chainlike structure of rubber is held responsible for its 
properties. In unstretched rubber these chains are tangled up 
in a very irregular fashion. When it stretches, they are, partially 
at least, straightened out. X-ray studies provide a confirmation 
of this. A beam of the rays passed through stretched rubber 
is scattered to form a regular pattern similar to that obtained 
by passing them through a crystal, where the atoms are 
arranged in a definite lattice structure. But unstretched rubber 
shows no such pattern. 

When the automobile industry began to assume importance, 
interest in a possible synthetic rubber was renewed. For exam- 
ple, in 1915, when the Germans found their rubber supplv cut 
off, they turned to a process which had been shelved a few years 
before. This produced methyl rubber, inferior to natural rubber. 
Nevertheless a factory with a 150-ton monthly capacity was 
operated until the armistice. The years following the war saw 
an effort by British interests to restrict the output of their 
plantations; this caused a rise in price, and renewed interest 
in synthesis. When, by 1926, production had begun in earnest 
in the Netherlands Indies, the laboratory work was dropped, 
with two exceptions. One was that of the Du Pont Company; 
the other, very significantly, was that of the I. G. Farbenindus- 
trie in Germany. But still synthetic rubber, in the sense of a 
test-tube product identical with that from trees, eluded the 
chemists, and even today has not been achieved. 

It began to be recognized that perhaps it need not be 
achieved that possibly the exact combination of atoms in 
rubber from Hevea was not necessarily the only one, or even 
the best. The approach then was to evolve new products which 


would also consist of the long chain molecules, or polymers, 
but which might be made of units entirely different from iso- 
prene. If these had physical properties similar to or better than 
rubber, little more could be desired. 

About this time Father Julius A. Nieuwland, professor of 
chemistry at the University of Notre Dame, was working, as he 
had been for most of his professional career, on acetylene, with 
little thought of rubber. In 1925, before a meeting of chemists 
at Rochester, he presented a paper describing some of the newly 
derived compounds which he had made from acetylene. Dr. 
Elmer Bolton, of the Du Pont laboratories, who was present, 
saw that some of these might solve his problem of creating 
synthetic materials such as rubber. The Du Pont group acquired 
the necessary patent and other rights, and by 1931 at a meeting 
of the Akron section of the American Chemical Society, they 
were able to announce success. 

Their product which made its debut as "Duprene," is now 
called Neoprene. Chemically, it is polychloroprene; that is, it 
consists of a chain of units called chloroprene. This is made up 
similarly to the isoprene unit, or monomer. It, likewise, has the 
row of four carbons and five hydrogens, but attached to the side 
is a chlorine atom, instead of the methyl ( CH 3 ) group. Ordinary 
rubber contains no chlorin, but in Neoprene it is present to the 
extent of 40 per cent. Strictly speaking, therefore, it is not 
synthetic rubber, though that term is now used, even in 
technical publications, to cover any synthetic compound which 
has approximately the physical properties of rubber. Occasion- 
ally a new word, "elastomer," is used to include rubber and all 
its man-made substitutes. 

Raw materials for Neoprene are coal, limestone and salt, all 
easily obtainable in the United States. First the coal and lime- 
stone are used to make calcium carbide, from which, when 
water is added, acetylene gas is given off. In the early days of 
automobiles the headlights burned acetylene, and the gas for 
them was made in the car, in a generator in which water dripped 
on calcium carbide. With the advent of efficient battery- 


operated electric lamps, acetylene passed out of the automotive 
picture, so it is curious that, in another way, it seems to be 

Father Nieuwland's contribution was a process by which, 
with the aid of catalysis, acetylene could be converted into a 
substance called divinylacetylene; but no synthetic rubber 
could be made from this. However, the process was slightly 
modified to produce monovinylacetylene, formed by the union 
of two acetylene molecules. This consists of a row of carbon and 
hydrogen atoms, almost the same as that to which the methyl 
group is attached in the unit of ordinary rubber. 

When the monovinylacetylene is acted on by hydrochloric 
acid (which is made from salt), chloroprene is obtained. Then 
comes the trick of persuading these links to join themselves into 
the chain. This is done by mixing chloroprene with soap, or 
some similar agent, and water, to form an emulsion. Normally 
only a few hours are required to yield the polymer of chloro- 
prene, which is Neoprene. 

From then on, the material is handled very much like rubber. 
It can be vulcanized, with the addition of sulfur, to increase its 
strength, although this is not necessary. In Neoprene alone 
among the synthetic rubbers, when it is heated there is a 
permanent change, similar to that of vulcanization, without the 
addition of other chemicals. In industrial use, however, it has 
been found more desirable to add certain other ingredients. 
The properties of Neoprene can also be varied by stopping the 
polymerization the joining together of the links before it is 
complete. But a stabilizing material is usually added, even when 
the full polymerization is reached. Otherwise, the linking may 
tend to go on too far, or else cross links may form among 
adjacent molecular chains. This would cause the material to 
stiffen while it is in storage. 

The basis of another type of synthetic rubber, which includes 
most of those made in Europe and a number from American 


factories, is butadiene. Above 23 Fahrenheit this is a gas. The 
structure of the molecule is similar to those we have met before 
a row of carbon and hydrogen atoms. At each end are CH 2 
groups, and in the middle are two CH groups, so it consists of 
four carbon atoms and six hydrogens. As a matter of fact, 
chloroprene may be thought of as chlorbutadiene that is, 
butadiene in which one of the hydrogens has been replaced by 

In Germany and Russia butadiene is prepared by a method 
very similar to that used for chloroprene, but using hydrogen 
instead of hydrochloric acid in the last step. The Russians 
proceed by chemically breaking up alcohol, made from the 
fermentation of grain or potatoes. In this country butadiene is 
made from the cracking of petroleum. In any event, the buta- 
diene must be very pure. Then, with the use of sodium metal 
as a catalyst, these units, when held for a period of days at a 
somewhat elevated temperature, link themselves together to 
form the polymer. 1 

The most popular of the German types, developed in the 
laboratories of the I. G. Farbenindustrie to provide tires for the 
panzer units, are those known as Buna S and Buna N. Here the 
butadiene links are alternated with links of another compound 
styrene in the case of Buna S and vinyl chloride in Buna N, 
which is also called perbunan. Chemigum, the synthetic rubber 
of the Goodyear Tire and Rubber Company, is reported to have 
a similar constitution, although the exact composition has not 
been revealed by the manufacturer. Probably Ameripol is 
similar. This was used by the B. F. Goodrich Company for the 
first automobile tires of synthetic rubber to be put on the Ameri- 
can market. 2 

1 This process was used in Russia and also, before 1939, in Germany. Another 
kind of Russian synthetic, known as Sovprene, is similar to Neoprene, contain- 
ing chlorin. 

2 The raw materials come from petroleum, gas and air, so the Goodrich Com- 
pany jointly organized the Hydrocarbon Chemical and Rubber Company as 
a subsidiary. They produce their synthetic rubber under the name of Hycar. 
Dr. Waldo L. Semon has been in charge of this development. Another krge 
oil company that is playing an important part in synthetic rubber development 


The clue to a great many of the characteristics of rubber and 
its relatives is the property known as "saturation." In the chart 
showing how natural and synthetic rubbers are formed (see 
Appendix, page 285 ) it will be noted that there are always four 
links, or bonds, connecting the carbon to adjacent atoms. 
Chemists express this by saying that the valence of carbon 
that is, the number of other atoms with which it will unite is 
four. But in some cases, as the chart shows, there are only three 
atoms around a carbon atom, and then one of the bonds is 
shown double. 

Such a condition is called "unsaturation"; and when it occurs, 
the carbon atom is always receptive to another atom of some- 
thing else, to use up the extra bond. When rubber is vulcanized, 
the sulfur atom grabs one of these double bonds and becomes 
attached to a carbon atom. But sulfur has a valency of two, so it 
grabs two carbons, in separate chains, forming a cross-linkage 
between them, and giving vulcanized rubber its strength. 

The trouble with natural rubber is that there are so many of 
these unsaturated double bonds. If sulfur is added and added 
to the point where all double bonds are eliminated, we have 
vulcanite, or "hard rubber" (from which combs were formerly 
made), a product by no means suitable for tires, raincoats or 
rubber bands. So in ordinary practice vulcanization is continued 
until the product has sufficient strength but is still elastic. This 
leaves a great many friendly carbon atoms with only three 
neighbors, and if they cannot get sulfur to unite with, thev will 
take something else, which often turns out to be oxygen from 
the atmosphere. The effect of oxygen is to weaken the rubber, 
and that is why tires and other rubber goods deteriorate while 
standing. The process is speeded by sunlight, and for that 
reason rubber should be stored as much away from sun and air 
as possible. 

In making butyl rubber, Dr. Frolich and the men working 

is the Standard Oil Company of New Jersey. At the Esso Laboratories, operated 
by the Standard Oil Development Company at Linden, N.J., Dr. Per K. Frolich 
and his colleagues have produced butyl rubber. 


with him found a means of controlling saturation. The isobutyl- 
ene groups, which form an important part of its molecule, are 
saturated because they have none of these loose ends. Just 
sufficient butadienes are put into the chain to give from one 
to two per cent of the unsaturation found in natural rubber; this 
will permit enough sulfur to combine to give the necessary 
strength. Then all the double bonds are gone! Exposing 
vulcanized butyl rubber to oxygen produces no deterioration. 
It is also resistant to other chemicals such as concentrated nitric 
and sulfuric acids, which quickly attack natural rubber. 

Rubber, natural or synthetic, can be molded because of its 
ability to be vulcanized. At first it is soft and can easily be 
shaped in molds or by other means. Then, while it is in the 
mold, the vulcanizing process introduces the necessary ties 
across from chain to chain and gives it strength. As a model, 
we might think of a fish net made of rubber bands which 
would not be very strong. Strength might be added by tying the 
rubber bands of the mesh together with relatively long parallel 
pieces of string. This would make the net stronger because the 
strings would impose a limit and prevent stretching to the 
breaking point, except with very great force. This corresponds 
to vulcanized rubber. But if the pieces of string were the same 
length as the rubber bands, the net would not stretch at all, and 
then we would have the condition of hard rubber. 3 

In addition to tires and electrical insulation, there are many 
other applications for synthetic rubber. Gasoline, fuel oil, kero- 
sene and similar liquids weaken the natural product, but many 
of the synthetics are highly resistant. These synthetic rubbers, 
even before the natural-rubber shortage imposed by the war, 

8 However, there are a number of compounds classed with synthetic rubber 
that, lacking double bonds entirely, are completely saturated and cannot be 
vulcanized; nevertheless they have many uses. One of these is Flamenol, made 
of units of polyvinyl chloride, which was developed for a heat-resistant electrical 
insulation by General Electric. Koroseal, made by the B. F. Goodrich Company, 
is similar; so is Vinylite Q, of the Carbide and Carbon Chemicals Corporation. 


were taking their place in refineries, filling stations, and in many 
parts of the automobile itself, and in airplanes also, where con- 
tact with oil would occur. They are used for vibration 
absorption, and this same property makes them useful for shoe 
soles and heels. Indeed, for every possible use of rubber a 
synthetic product will probably serve. 

In his American Chemical Society report, Dr. Frolich well 
summarized the situation in regard to the possibilities of syn- 
thetic rubber. He says: 

Originally the goal of those working in this field was to synthesize 
a product that would equal natural rubber in those properties which 
have contributed to make it one of our most important structural 
materials. The more recent trend is to synthesize materials closely 
resembling Nature's product m some respects, while at the same time 
surpassing it in others. In the light of achievements to date, we are 
justified in looking forward to the development of a series of syn- 
thetics, each one of which will exceed natural rubber in certain prop- 
erties; in the aggregate, therefore, these products will give us some- 
thing superior to rubber as we know it today. 

The future of synthetic rubber therefore seems promising. 
Spurred by war needs, supported by government subsidies, large 
manufacturing plants were put under construction, boosting 
many fold the production of synthetic rubber over what it was 
only a short while ago. Approximately 17,000 tons were made 
in 1941; but plans called for a production of well over 400,000 
tons a year in the near future. Yet, although raw materials are 
cheap and plentiful, perhaps the cost can never be reduced low 
enough to compete with natural rubber at its pre-war rate of 
ten cents a pound or less. In our post-war economy, therefore, it 
is likely that natural rubber, perhaps from Central and South 
America, and synthetic rubber as well, will both have their 
places. Tires may be made with a body of natural and a tread of 
synthetic rubber; and other combinations may be used. But at 
least we will no longer be at the mercy of a foreign and hostile 
power in securing such a vital material. 

VII. Chemistry and the Farmer 

From time immemorial the aim of agriculture has been to 
produce food. As farmers' methods were improved, the aim was 
to make two blades of grass grow where one grew before. This 
has had an important economic effect it has, for instance, been 
largely responsible for invalidating the fears of Malthus that 
the world's population would be limited by the food-producing 
facilities known in his day. ( Malthus died in 1834. ) Increased 
efficiency, and the opening, which Malthus did not foresee, of 
vast new farm lands, finally resulted instead in the absurd situa- 
tion where farmers in 1934 were paid for the crops they did not 

The past decade, however, has seen another and more scien- 
tific approach to the problems of agriculture; one which already 
has had important results. It is not to create more crops but to 
find more uses for those we have. Like oil wells and mines, 
farms are now to provide raw material for industry; and to 
describe this the word "chemurgy" has been coined the first 
part from our familiar "chemistry," the second from the Greek 
"ergon," meaning work. The idea conveyed is "chemistry at 
work." In 1935 the Farm Chemurgic Council was established, 
with the backing of a group of prominent scientists as well as 
representatives of industry and agriculture. Its avowed object 
is "to advance the industrial use of American farm products 
through applied science." Since its founding, largely through 
its meetings, the Council has done much to further this aim, and 
to give farmers a new outlet for their crops and other products. 

Milk forms an excellent example of the possibilities of this 
chemurgic resolution of the farm problem. With its products 
worth more than $3,000,000,000 annually, the dairy industry 
surpasses the automobile industry and the steel industry in 



size. With 25,000,000 cows, worth about $1,500,000,000, as well 
as the many millions of dollars invested in farms and equip- 
ment, it is truly important. And its value to the farmer is shown 
by the fact that milk brings the farmers more income than any 
other single crop. 

Of the 50 billion quarts of milk processed annually out of 
air, water, salt and grass by the nation's cows, about 42.5 per 
cent is sold as fresh milk or cream. Butter making takes some 41 
per cent, and six per cent goes into cheese. For evaporated and 
condensed milk, 4.5 per cent is required; ice cream takes some- 
what more than three per cent, and malted-milk powder and 
other miscellaneous uses account for the three per cent 

With this apparent 100-per-cent usage, it might seem that 
there is none left over, but Dr. L. K. Riggs l assured his hearers 
at a recent meeting of the Farm Chemurgic Council that this is 
fallacious. He said: 

When fresh milk goes into a bottle, or into a powdering or con- 
densing process, that's that. The entire quantity is disposed of. But 
when milk goes to the butter or cheese manufacturer, his main inter- 
est is in only one part of that milk the butterfat. When he runs a 
hundred quarts of milk through a cream separator, he ends up with 
roughly four quarts of cream which he can use in his operations, and 
ninety-six quarts of skim milk which he can't. 

Consider that it takes the cream from ten quarts of milk to make 
a pound of butter; consider too that the country's annual butter pro- 
duction exceeds two billion pounds and it's easy to see why the 
skim milk from this one source alone assumes torrential proportions. 
As a matter of government record, the amount of skim which results 
from butter, ice cream and bottled cream operations totals twenty- 
five billion quarts a year. But that's not all. By the time the butter 
makers get through with their churning process they have about a 
billion and a third quarts of buttermilk on their hands in addition to 
the skim milk. 

From 3,750,000,000 quarts of milk used to make the vear's 
output of 700,000,000 pounds of cheese, nearly three billion 

1 Director of research of the Kraft Cheese Company, which is a division of 
National Dairy Products Corporation. 


quarts of cheese whey are left. And a billion quarts of casein 
whey remain after skim milk has been processed to remove the 
casein. All told, this is 30 billion quarts of liquids left over, 
containing many products of potential value. 

As skim milk comes from the separator spout, stated Dr. 
Riggs, "it has everything in it that was present in the whole 
milk, with the exception of the butterfat, Vitamin A, and Vita- 
min D content. That means the skim carries substantial values 
of Vitamin Bj and Vitamin B 2 , proteins especially casein and 
albumin lactose and minerals. Buttermilk has much the same 
constituents as skim milk, while whey is rich in proteins, lac- 
tose, minerals and riboflavin (Vitamin B 2 ). Multiply the ele- 
ments found in a single quart of these liquids by the thirty 
billion quarts available then consider the wide range of indus- 
trial uses already found for these substances, and there can be 
little doubt of the justification for continued research." 

At present some six billion quarts, or about a fifth of the to- 
tal, find a use, mostly for making casein. The chief use of the 
rest is as food for livestock. 

Casein is an important industrial material. For example, it 
can be made into a plastic which is widely used for buttons, 
buckles, beads, game counters and the like. This is produced 
in sheets, rods or disks, which are already hardened, and can 
be cut or ground to the desired shape. For buttons, however, 
blanks are formed from the soft mixture of the casein with the 
plasticizer. Not having been "cured," they can easily be shaped 
to the form wanted. Then they are put through a formaldehyde 
bath for hardening. They have the disadvantage of absorbing 
moisture rather freely; but as they are easily colored, machined, 
and polished, and are non-inflammable, they have been quite 
popular, under the trade names of Ameroid and Galorn. 

Among its many other industrial uses, casein is made into 
paint. It can be mixed with nothing more than cold water, yet 
when applied it gives a permanent coat which is insoluble and 
can be washed. In some forms, it has been adapted for out-of- 
door use. Since it is quite opaque, it easily covers and hides 


older surfaces, making one coat usually sufficient. Delicate color 
effects can be obtained with the mixture of proper pigments, 
and, as it does not yellow with age, these are durable. 

The principal uses of casein, however, are for making book- 
binding and woodworking glue, and as a coating for paper, 
which, at present, employs more casein than all other applica- 
tions combined. In a particularly pure form, it is also used in 
medicine. Though there are plenty of outlets for casein, and 
there is plenty of skim milk to supply it, the trouble is that it is 
not in one place but scattered around the country in hundreds 
of thousands of puddles on dairy farms. One remedy, perhaps, 
would be to devise a simple machine by which the farmer him- 
self could turn his skim milk into casein. As this takes up con- 
siderably less room than the liquid, it would be much easier to 
ship to plants in a position to put it to work. 

A synthetic wool-like fiber from casein is another possibility. 
A few years ago this was produced in Italy under the name of 
Lanital. Fibers are spun in an acid bath, and have many prop- 
erties of wool, but they are not as strong. This weakness is espe- 
cially evident when they are wet. However, the Bureau of Dairy 
Industry of the U. S. Department of Agriculture, and com- 
mercial groups, such as the Atlantic Research Associates, an 
affiliate of National Dairy Products Corporation, have done con- 
siderable research in the field. Where used in fabrics, the fiber 
is always mixed with an equal, and often a greater, amount of 
natural wool. 

The casein fiber of the Atlantic Research Associates, marketed 
under the name of Aralac, has also had a use that savors of 
magic it takes rabbits out of men's felt hats. Felt is believed 
to have been discovered by some unknown primitive shepherd. 
Probably he took some wool from his sheep and made a little 
cushion to put in the heels of his shoes. Warmth, moisture and 
pressure turned this into felt. Today wool felt is largely used 
for women's hats, while men's hats are made of felt prepared 
from rabbit fur. But now manufacturers mix casein fiber with 
the rabbit fur, and find it advantageous in many respects. Since 


two or three rabbits are required for an ordinary hat, the use 
of just a third of casein fiber pulls a rabbit out of each hat 
so made! 

Skim milk is a by-product of the dairy industry, but even 
after the casein has been removed there is a further by-product 
whey, familiar as part of Little Miss Muffet's favorite diet. It 
is a watery liquid, still containing some important food ma- 
terials, such as protein and milk sugar. Of the seven per cent 
of solid matter in whey, about 75 per cent is milk sugar, or 
lactose. It has been used in a dried, powdered form, for feed- 
ing to children and adults who do not otherwise have enough 
minerals in their diet. This, however, accounts for only a minute 
proportion of the total; most of the whey produced is either 
thrown out or fed to the pigs. 

Under the direction of Dr. B. H. Webb, the Bureau of Dairy 
Industry has devised a use of whey in the form of candy, called 
"Wheyfers." They are something like molasses chips, but with 
quite a different flavor. Usually they are coated with chocolate, 
partly for taste, but largely to keep them from absorbing mois- 
ture, which they easily do in humid weather. Fudge and cara- 
mels can also be made from whey, as Dr. Webb has shown. 

With a number of industrial and pharmaceutical uses for the 
lactose, the lactic acid, and the sodium, calcium, iron, copper 
and other lactates which can be prepared from whey, this also 
is potentially an important raw material. If the problem of col- 
lecting can be solved, milk may some day be as important in 
industry as it now is in the business of supplying food to a 

Then again there is the soy bean, grown for ages in China, 
where it has formed a principal part of the diet. In 1804 it was 
introduced into the United States, but only in the last few 
decades has it achieved any great importance here largely 
through the encouragement of the Ford Motor Company. It 


can be grown, in general, in any climate suitable for cotton or 
corn, and it is fairly simple to cultivate. In recent years two 
quarts of soy-bean oil for the enamel, and an equal amount in 
the form of glycerine for the shock absorbers, have gone into 
every Ford automobile. Not only glycerine and enamel but also 
explosives, varnishes and paints, soaps and printing inks are 
products into which the soy bean may enter. 

It can be used, too, for plastics; and these are similar to those 
made from casein, since the main ingredient of the soy bean, 
like casein, is a protein. However, soy-bean plastics have not 
yet reached a state of commercial development, largely be- 
cause of difficulty in molding methods. Several concerns are 
engaged in research, and as a result of their efforts the high 
water absorption of these materials, like those from casein, has 
been reduced. Where formerly the absorption was about two 
per cent after 25 hours of immersion, it has now been reduced 
to less than a third of this figure. 

Soy-bean fiber has been advanced somewhat further, as we 
noted in our discussion of "chemical clothes." According to the 
1942 Plastics Catalog, the average production of an acre of soy 
bean is about 25 bushels, in which there are some 600 pounds 
of protein. This in turn contains at least 500 pounds which may 
be converted into the soy-bean protein fiber. First the oil is 
extracted, and becomes available for the various other uses. 
The protein is prepared from the meal that remains, and is dis- 
solved to give a thick, stringy solution, from which the fibers 
are spun. Following an after-treatment, a white or light-tan 
fiber is the result, one which 'lias a very warm, soft feel, natu- 
ral crimp and a high degree of resilience and flexibility." It 
does not wet as readily as casein fiber, and is more resistant to 
the action of mold. Since it can be handled on the machinery 
used for ordinary cotton and worsted, it may well be an im- 
portant product in coming years, and find uses in clothing and 
upholstery, particularly when mixed with wool, rayon or cot- 



Other crops that the farmer grows have possibilities as well. 
Idaho, for example, is famous as the native state of the "big 
baked potato," yet, in grading out the big ones, vast amounts of 
smaller ones, called cull potatoes, are left over. Some can be 
fed to stock, but this takes only a small proportion and the 
rest are wasted. However, potatoes contain starch, and starch 
is most useful industrially in many ways besides the stiffening 
of collars and shirts. 

Starch plays a part in explosives manufacture. At a recent 
meeting of the Farm Chemurgic Council, R. E. Gale, of the 
Idaho Power Company, told how one region of his state decided 
to use the cull potatoes for starch manufacture. Speed was es- 
sential, because it was then early summer and the starch pro- 
duction had to be under way in October if the year's crop was 
to be caught. Priority troubles making it impossible to get new 
machinery, a beet-sugar factory, then being dismantled some 
600 miles away in Utah, was purchased; and the machinery, 
supplemented with some other parts obtained from the auto- 
mobile junk yard, was brought to Idaho. Now the starch mill is 
at work. The big potatoes still are shipped to market, while the 
smaller ones pay their way as starch. 

From zein, a protein present in corn, it may also be possible 
to make a plastic, though this is still in the very early stages of 
experimentation. However, corn is an important source of many 
chemicals used in major industries. 

For instance, the Commercial Solvents Corporation, which 
makes not only the solvents used to carry other chemicals but 
also many that are themselves vital parts of reactions in indus- 
trial chemistry, has cited compounds such as acetone, butanol, 
methyl (wood) alcohol, ethyl (grain) alcohol, and a number 
of others which can be produced from corn. Acetone has uses in 
such varied fields as explosives, the making of viscose, or cellu- 
lose acetate fiber, photographic films, and plastics from cellu- 
lose nitrate. Butanol is used in lacquers, photographic films, 


artificial and patent leathers, to make synthetic resins, and in 
dry cleaning, to mention only a few. Methyl alcohol has uses 
such as the manufacture of formaldehyde, dye solvent and 
anti-freeze; and it is also important in the making of plastics. 

All these products can be derived from natural gas and 
petroleum, but Commercial Solvents largely uses corn as the 
source. Nearly two bushels of corn are consumed in making the 
lacquer for a single automobile; the lacquer also is used to make 
a surface on toys and locomotives. This one company has a 
capacity for converting 11,000,000 bushels of corn annually into 
chemicals. Here is an example of what can be done with an ex- 
cess of one crop. It is not necessary to destroy the surplus, or to 
resort to drastic means of restricting its production, when it 
can be processed in ways so useful to all. 

Despite the use of structural iron and steel, wood, the oldest 
of building materials, maintains its position of importance; a 
position lately enhanced because of the shortage of metals. But 
cutting logs into boards is an unavoidably wasteful process, in 
which many chips and trimmings are left. To get big boards, big 
trees are needed which yield big logs. But they take time to 
grow, and smaller boards must be used. That means more joints 
and greater expense in putting the structure together. 

In the past, lumber mills always had great waste burners 
where chips and other leavings went up in smoke. But in many 
Southern mills this has been eliminated since William H. Mason 
found a means of turning these very wastes into a product called 
Masonite a building material of great utility. Today Mason- 
ite is in some ways superior even to the boards which formed 
the main output, and from which the smaller bits were "waste/' 

The nucleus of the entire process is the so-called Masonite "gun" 
from which the wood is exploded. Wood chips of suitable moisture 
content are loaded into guns, which are cylindrical steel vessels of 
from twelve to twenty-six cubic feet capacity, equipped with a quick 


opening hydraulic valve at the bottom. When full the gun is closed 
and steam admitted to a pressure of 600 pounds; this requires about 
30 seconds. The pressure is then quickly raised to 1000 pounds, and 
held there for approximately one to two seconds, at which point the 
bottom valve is opened and the entire contents of the gun discharged 
into a cyclone which separates the fiber from the steam. 

This action not only explodes the chips into a mass of finely divided 
fiber, but also has a definite chemical action on the wood constituents. 
Less than one minute elapses from the time the gun is loaded with 
wood chips until the resulting fibers are discharged into the cyclone. 
The stock is then refined to the desired degree, the wet-lap formed 
on a special type of board machine, and after being cut into twelve- 
foot lengths, the wet-laps are conveyed, 20 sheets at a time, into the 
hydraulic presses. The length of time the board is in the press, and 
the temperature and pressure to which it is subjected, are determined 
by the density, thickness and type of board desired. In addition, the 
gun operation can be varied over a wide range of conditions, which 
in turn gives rise to a wide variety of exploded material, and makes 
possible the various types of board products. 2 

The most densely packed material that can be made from 
wood in this way is a substance resembling marble, called 
Benalite. Since it weighs above 90 pounds to the cubic foot, 
there are practically no voids left between the fibers, so further 
pressure is unable to compact it more. At the other extreme is 
Cellufoam, with a density of slightly more than a pound per 
cubic foot. In between these are a number of others with their 
own characteristics. Yet they are essentially all wood, for or- 
dinarily no fillers, binders or other molding materials are added. 

Wood consists, to the extent of about 50 per cent, of cellu- 
lose. This is the principal constituent of paper, which, if the 
other components of wood are allowed to remain, is weakened. 
Consequently, paper makers try to remove the non-cellulose 
constituents. So called "wood sugars," technically "hexosans" 
and "pentosans," make up about 20 per cent of wood, while the 
remaining 30 per cent is lignin, the exact composition of which 
is still an unsolved problem of chemistry. 

In making Masonite the lignin remains, and is used. Dr. 

2 Roger M. Borland: First Annual Southern Chemurgic Conference, Nash- 
ville, Term.; June 17, 1941. 


Dorland, director of Masonite research, is authority for the 
statement that it may be considered as the binding material 
between the wood fibers; that the explosion process separates 
them, and activates the lignin in some peculiar way, thus en- 
abling it to weld the fibers together again when heat, moisture 
and pressure are applied. Unlike the "paper type bond," which 
is strong when dry but becomes weak when wet, this is a "wood 
type bond," strong both wet and dry. 

This process resembles the manufacture of thermosetting 
plastics, already described. As with the synthetic resins which, 
once set, cannot be softened again by any simple process, the 
rebonding of the lignin is not reversible by any normal treat- 
ment. That is, a piece of the material cannot be defibered and 
then put together again as effectively as before. It was a study 
of the Masonite process, and the realization that the lignin ac- 
tually passes through a plastic state, that led to an investigation 
of the extent to which this quality could be developed. The re- 
sult was the hard, dense material called Benalite, made nor- 
mally under 1500 pounds pressure per square inch. 

Even in making Masonite, the 20 per cent of wood substance 
called "hemi-celluloses," which are neither cellulose nor lignin, 
are not wanted. As they are soluble in water, the obvious 
method of removal is to flush the fiber with large quantities of 
water. While this removes them, the resulting solution is too 
dilute to make practicable any use of the chemicals it contains. 
However, an extracting method has been devised which re- 
moves them in a more concentrated form. The "sugars" ob- 
tained may be converted into acetic acid, formic acid, wood 
alcohol, butanol, acetones, glycerine, and other chemicals im- 
portant in industry. And even the lignin, which is not wasted in 
the Masonite process, but is lost in the paper mills, also can be 
salvaged, for it is a source of vanillin, the active principle of 
vanilla extract. Since the supply of natural vanillin was cut off, 
this has almost entirely replaced the bean extract. The next 
plate of vanilla ice cream you eat may have been flavored with 
a product obtained from an odorous and dirty liquid which was 


once the waste from a pulp mill. The "magic" of chemistry has 
converted it to a product which is even purer than the natural 
extract! 3 

In many parts of the South pine grows luxuriantly but the 
land is not very suitable for other crops; the South needs new 
industries, and the United States should be independent of 
imports as far as possible. Considerations such as these have 
resulted in an increasingly important paper industry along the 
southeastern seaboard, largely as a result of the researches of 
Dr. Charles H. Herty, professor of chemistry at the University 
of North Carolina until his death in 1938. 

Paper had been made from southern pine, especially Kraft 
paper for wrapping, long before Herty 's investigations. For such 
paper, color is not important. Some was made into white paper 
and, though the bleaching process increased the cost, the orig- 
inal material was so cheap that the product could still compete 
in the open market. Herty, then, did not invent a new process 
of paper making. Only slight changes in standard methods, used 
in other places to make news print from woods such as spruce, 
were needed to make it of equal quality from pine. His real con- 
tribution was stated thus by Dr. Harrison E. Howe at the time 
of Herty's death: 4 

He succeeded in demonstrating the usefulness of southern woods, 
notably pine, as a pulpwood, and the effectiveness of the sulfite proc- 
ess for treating it. Many of his friends believed that he had developed 

3 Oxalic acid, useful in making celluloid, rayon, leather, textiles and other 
vital materials, is another chemical that may be obtained from wood. Dr. Donald 
F. Othmer, head of the chemical engineering department of the Polytechnic 
Institute of Brooklyn, described an inexpensive process of making it from saw- 
dust at a recent American Chemical Society meeting. He said that 100 pounds of 
dry sawdust, of which some 8,000,000 tons a year are burned or wasted, will pro- 
duce about $8.00 worth of chemicals; not only oxalic acid, but also acetic and 
formic acids and wood alcohol. Only lye, lime and sulfuric acid, all cheap and 
readily available, are needed. Out of 100 pounds of dry sawdust can be made 
50 pounds of oxalic acid, 14 pounds of acetic acid, and four pounds each of 
formic acid and wood alcohol. These, in normal times, would sell for $7.94. 

* Industrial and Engineering Chemistry. September, 1938: p. 963. 


an essentially new process and by publicizing that belief created ill 
will for the project among those who knew all the facts. Dr. Herty had 
demonstrated that by using young trees many difficulties could be 
avoided, but he developed no really new process nor did he ever 
claim to have done so. He was able as a crusader to call attention 
again to the potential resources of the southland and to ways in 
which rapidly growing trees could be utilized. 

Certain species of these pines require less than a score of 
years from the seed to the full growth; and if two or three adult 
trees to the acre are left standing, the ground is reseeded with- 
out human attention. In a single acre as many as 40,000 seed- 
lings may spring up. Obviously, all cannot grow, and they must 
be thinned to about 400 per acre during the first few years. 
However, many of those that are to be removed may be left 
until they have grown large enough for pulp. Those remaining 
after the first decade are large enough to yield turpentine for 
another eight to ten years. Then they may be cut for timber. 
In this way, three different crops are obtained from the same 
planting of trees. However, because of difficulties in synchroniz- 
ing their activities with others, the pulp makers have been 
rather loath to put such a system into effect on a widespread 
scale, and prefer instead to harvest all their young trees when 
they will give the maximum yield. 

Cotton, of course, is the great crop of the South. Here also 
chemurgy is paving the way, both to improving old uses of 
cotton, so that it can compete more successfully with newer 
products, and to developing new uses. In 1937 a group of pri- 
vate individuals in Tennessee founded the Cotton Research 
Foundation. Most of the Foundation's work is done by a group 
working at the Mellon Institute in Pittsburgh, admirably suited 
to take on such a project. 

All the parts of the cotton plant are being studied, even the 
hulls and the stalks, which were formerly wasted. The bran 
obtained from the hulls can be made into an economical and 
effective compound for sweeping. The stalks can be used for 
making wallboard and similar products, though the commercial 


possibilities of this process remain to be explored fully. Cotton 
linters (the fuzzy stuff that sticks to the cottonseed after it 
has gone through the cotton gin, and the longer fibers, making 
up the lint, have been removed), has long been used for stuffing 
upholstery. During World War I it found wide application 
chemically in the making of nitrocellulose explosives. Follow- 
ing the war, uses for it were developed in the rayon and plas- 
tics industries, though improved types of wood pulp have pro- 
vided keen competition. The Foundation is studying the prop- 
erties of the linters with a view toward restoring this use. 

Cotton cloth itself, of course, is being studied. For example, 
cotton sacks as containers have been replaced in recent years 
by paper bags for many products. Largely this has been on 
account of the greater resistance of paper to penetration by 
dirt and water. Part of the research has therefore been directed 
to improve resistance of cotton and to give it the advantages 
both of paper and cloth. 

Peanuts form a crop that is grown in all of the Southern 
states; and these "goobers" are mostly used as food for man and 
beast. From the shelled nuts, oil (about 35 per cent) and meal 
(65 per cent) are obtained. The peanut meal makes a feed of 
high protein content for livestock. But, although these are the 
main purposes for which the peanut is utilized, there are 
chemurgic possibilities, many of which have been developed 
by the Negro chemist, Dr. George W. Carver. For instance, 
the oil is used in soaps, while the peanut itself can probably en- 
ter into plastics in much the same manner as the soy or coffee 
bean. From peanut shells has been made a heat insulating ma- 
terial nearly equal to cork in efficiency yet, on large-scale pro- 
duction, costing about 35 per cent less. And also from the pea- 
nut can be made breakfast food, ice-cream powder, inks, dyes, 
cosmetics and a flour containing a high percentage of protein. 

Other nuts have important chemurgic possibilities, and in 
many cases may prove useful substitutes for raw materials that 
had been imported before the war. English walnuts are exten- 


sively cultivated in the United States, and promise the pos- 
sibility of 100-per-cent utilization. The meat contains about 65 
per cent of oil, which can be pressed out either hot or cold. 
If cold, the oil is pale and can be used in food, while the hot- 
pressed oil is useful in soaps and paint. Artists' colors have long 
been mixed with walnut oil, particularly in Europe, where it 
has been prepared for many years. Recently production has 
started in some of the shelling plants on the Pacific coast. 

A fine flour made from ground walnut shells is valuable as 
a base for insecticides, carrying the poisonous principles with- 
out loss of potency until they are applied. Plastics, fire brick and 
dynamite are still other applications for this flour. And almonds, 
pecans and filberts too have many uses, other than as a delicious 
food. At the Georgia School of Technology pecan oil was mixed 
with white wax, borax, water and perfume to make a fine grade 
of cold cream; while pecan meal, made from the kernels after 
the oil has been extracted, can be blended with wheat flour in 
baking. So nuts may eventually form another outlet for the agri- 
cultural energies not only of the South, but of other parts of 
the country as well. 


As has been remarked, we often hear estimates of the future 
duration of our natural supplies of coal and oil, and, while many 
pessimistic views of the past have been proven wrong, there is 
no doubt that those resources are limited; that they are being 
used in a time far shorter than the natural processes that made 
them. But even here farm chemurgy may some day help out, 
for researches by Dr. Ernst Berl, at the Carnegie Institute of 
Technology in Pittsburgh, show the possibility of converting 
any form of cellulose, such as hay, sugar cane or cotton, into 
coal and oil. These experiments must be carried much farther 
before they reach commercial practicability, but that time is 
in sight. And this will help to realize the prophecy made at the 


First Farm Chemurgic Conference, in May, 1935, at Dearborn, 
Michigan, by Henry Ford, who said: 

I foresee the time when industry shall no longer denude the forests 
which required generations to mature, nor use up the mines which 
were ages in the making, but shall draw its material largely from the 
annual produce of the fields. I am convinced that we shall be able to 
get out of yearly crops most of the basic materials which we now get 
from forest and mine. The time is coming when we shall grow most 
of an automobile. The time is coming when the farmer in addition 
to feeding the nation will become the supplier of the materials used 
in industry. 

VIII. Chemicals for Cures 

On the fateful Sunday morning of December 7, 1941, the 
Japanese may have found us unprepared in many ways. But this 
cannot be said for the medical forces of the U. S. Army in 
Hawaii. Many months before, under the direction of Colonel 
Edgar L. King, surgeon-in-charge, the medical units of the 
Army and Navy had been organized to meet the necessity that 
finally arose. Immediately after the attack two leading medical 
men from the mainland, Dr. Perrin H. Long of the Johns Hop- 
kins Medical School and Dr. I. S. Ravdin, Harrison Professor 
of Surgery in the University of Pennsylvania Medical School, 
flew out to Hawaii to study conditions. On his return, Dr. Rav- 
din reported that they "both felt that we were witnessing the 
inauguration of a new era in military medicine. It has been 
repeatedly said by great generals of the past that an army is no 
better than its surgeons. If the experience in Honolulu is to be 
taken as an expression of the type of medical service our armed 
forces are to receive, we can be sure that in the end victory 
will be ours." 

During World War I, more than three-fourths of the men 
who sustained abdominal wounds died as a result of infection; 
but infection was almost completely absent following the Pearl 
Harbor attack. There were a few amputations required, where 
limbs had actually been hit by shell or bomb fragments, but 
none because of infections. Yet during 1914-1918 at one hos- 
pital 47 per cent of the amputations were caused by infections 
of gas gangrene alone. In December, 1941, wounds healed 
quickly and cleanly. Even though their injuries would un- 
doubtedly have been fatal in an earlier period, the men re- 
covered rapidly, and were soon anxious and able to join the 
fight once more. 



In England, following Dunkirk, comparable experiences had 
been reported. For example, one group of 266 wounded men 
showed no infections from tetanus or gangrene, no fatalities, 
and only one amputation, resulting from extensive injuries 
which had caused severe bleeding. By a sort of ironic justice, 
the developments that made possible this record had their be- 
ginning in Germany, though medical laboratories in the United 
States, Great Britain and France played no small part in giv- 
ing them their effectiveness. 

In 1908 an Austrian student named Gelmo discovered a com- 
pound which was given the name "sulf anilamide"; and this he 
described in the thesis he submitted to the University of Vienna 
to qualify for his doctor's degree. However, neither he nor any- 
one else at the time could think of any uses for it, though the 
following year chemists of the I. G. Farbenindustrie, the Ger- 
man dye trust, did try it in an effort to make dyes more fast. 
In 1919 two German doctors noticed that it killed bacteria, but 
they made no further study of its effects. 1 

By 1933 the Germans had a drug really a red dye called 
"streptozon," which had been developed by Gerhard Domagk, 
the director of the Elberfeld Research Laboratory of the 
Bayer Company, one of the units of I. G. Farben. Streptozon 
cured mice that had been inoculated with virulent streptococci. 
Probably its first application to a human subject came in 
1933, when it saved a ten-months-old boy in Diisseldorf from 
death by blood poisoning. Since this infection had been caused 
by another germ, the staphylococcus, instead of the streptococ- 
cus, "streptozon" no longer seemed appropriate and the name 
"prontosil" was applied to that drug. In 1935 Dr. Domagk pub- 
lished a paper in which he presented convincing evidence of 
the value of his discovery in combatting infection. 

1 Such varied attempts at application of a compound are not unusual. It was 
in 1904 that Dr. Paul Ehrlich and his Japanese associate Dr. Kyoshi Shiga had 
found that a mouse infected with the one-celled animal, trypanosome, could 
be cured through the use of a certain red dye. From these researches came 
salvarsan, which proved a potent cure for syphilis, since, without killing the 
victim of the disease it destroyed the spirochaete that caused it a process 
until then impracticable. 


His results were quickly confirmed as excited medical re- 
search men in various countries began to study them. A group 
of workers in France demonstrated that even better than the 
dye itself was a colorless component. This turned out to be 
the same sulfanilamide that Gelmo had first isolated in 1908. 
But even before this was done, doctors had started to take ad- 
vantage of prontosil, and it gained wide publicity in the United 
States when it was used effectively on Franklin D. Roosevelt, 
Jr., for a streptococcic infection of the throat. In 1939 Dr. 
Domagk was awarded the Nobel Prize in Medicine; but his gov- 
ernment would not allow him to accept it. 


Dr. Long of the Johns Hopkins, one of the two physicians 
who later made the trip to Honolulu, was mainly responsible 
for the introduction of sulfanilamide in the United States. One 
of its first sensational successes was in 1936 when a twelve-year- 
old boy in a Washington hospital was suffering from a most 
virulent type of meningitis. This is an inflammation of the 
meninges, the membranes of the brain and spinal cord. One 
deadly form is caused by the hemolytic streptococcus; and of 
the many cases that up to then had been treated at the Johns 
Hopkins, only one had recovered the death rate was higher 
than 99 per cent. Yet this was the type from which the boy 
was suffering. 

Two days before Christmas he was given sulfanilamide two 
days after Christmas he was showing definite signs of recovery. 
By mid-January he was well! And since then the death rate 
from this dread disease has been reduced to less than fifty per 

A dramatic demonstration of what sulfanilamide can do for 
wounds came in 1938 when fire in a Minnesota hotel resulted in 
fifteen deaths. Two men jumped, breaking their legs and sus- 
taining compound fractures the kind in which there is a 
wound with an opening from the break to the surface of the 


skin. Physicians treating these men sprinkled powdered sulf anil- 
amide into the open wounds, and they healed without any in- 
fection, though previously perhaps a quarter of all compound 
fractures had become infected. Since then, this treatment has 
been routine in compound fractures; and as a result infection 
has become almost unknown. 

Today sulfanilamide, still widely used, is supplemented with 
three other "sulfa" drugs closely related to it. These are sulfa- 
pyridine, sulfathiazole and sulfadiazine. A fifth, sulfaguana- 
dine, has also proven of value for certain diseases, notably bac- 
terial infections of the intestines, where it is absorbed slowly, 
after being taken through the mouth, and remains more con- 
centrated than others, which quickly enter the walls of the in- 
testine and the blood supply of the body. 

With the success of sulfanilamide in some diseases demon- 
strated, it was soon tried on a variety of others, and, while some 
yielded to it, others did not seem to be affected. Pneumonia was 
one in which the results were disappointing, so researches were 
made to find some compound that would do for the pneumo- 
coccus what sulfanilamide did for the streptococcus. Yet, as 
with all these chemicals that cure, it had to be relatively non- 
poisonous to the body itself. 

In May, 1938, a British scientist, L. E. H. Whitby, reported 
that he had found the desired drug in one of many compounds 
prepared in the chemical research laboratories of May and 
Baker, Ltd., a large English pharmaceutical house. Referred to 
at first by its laboratory serial number, "M. and B. 693," it was 
later called sulfapyridine, rather than its full chemical name of 
2-sulfanilyl aminopyridine. Whitby's results had been obtained 
with pneumococcic infections in mice; but soon after they were 
announced two other English physicians, Drs. G. M. Evans and 
W. F. Gaisford, reported that it had proven effective in clinical 
studies of human patients. They gave sulfapyridine to approxi- 
mately every other pneumonia patient admitted to a hospital, 
until they had had two hundred cases. Of these, one hundred 


had the best routine treatment up to that time. The others re- 
ceived the new drug. Of the first group, 27 died, but only 8 
died among those who received sulfapyridine. 

Other medical men tried it and reported results, in some 
cases, even more striking. By the autumn of 1938 Merck and 
Company had introduced the drug in the United States, and 
during the following winter some 18,000 cases were treated. Of 
3,005 cases during that season on which detailed analyses were 
made, only six per cent were fatal; a far better record than 
could have been achieved earlier. 

Sulfanilamide, in the famous Diisseldorf case in 1933, had 
been used for fighting staphylococcus, which is the common 
cause of such ills as boils and other infections that are accom- 
panied by the formation of pus. However, in the United States 
sulfathiazole was developed, and it proved much more effective 
against this germ. The latest member of the family, sulfadiazine, 
is also of American origin. It appeared in 1940; and clinical 
studies have indicated that, for a majority of the uses in which 
the sulfa drugs have value, sulfadiazine is just as effective, and 
less poisonous to the patient than the others. 

Various ways are used for administering the sulfa drugs. Or- 
dinarily they are given in the usual manner, by the mouth. 
Then the drug goes through the intestines, where it is absorbed, 
and enters the blood stream. But sometimes this may not be 
quick enough, especially in treating war cases. Dusting the 
powdered drug on the wound itself gets it to many of the germs, 
but hypodermic injection is sometimes desirable. One method 
that has been suggested is with another chemical, closely re- 
lated to sulfanilamide, which can be prepared in a solution in 
water which has just about the same degree of acidity as the 
blood. Carried to the liver and the kidneys, it breaks down to 
give sulfanilamide, which then can do its work. When a pa- 
tient is very ill, also, the drug may be given through the rectum. 

For a few hours the concentration of the drug in the blood 
rises, but then it goes down, and most is excreted through the 


kidneys. To keep it constantly acting, therefore, it is necessary 
to continue giving the drug at four-hour intervals, day and 
night, if the greatest effect is to be obtained. 

In wounds, the sulfa drugs must be in contact with the germs. 
Therefore dead flesh must be cut away so that it will not in- 
terfere. The drugs seem to interfere in some way with the life 
processes of the bacteria, perhaps lowering their rate of re- 
production; and then the phagocytes the white corpuscles of 
the blood have more opportunity of devouring them. 

Of course, sulfa drugs are no panacea no such universal 
remedy has yet been discovered. The victims of some diseases, 
notably tuberculosis, infantile paralysis, influenza and the com- 
mon cold, have shown little or no improvement when treated 
with them. Even diseases for which the sulfa drugs are effective 
are not conquered one hundred per cent; sometimes strains of a 
species of bacterium which is ordinarily destroyed develop re- 
sistance, even during the course of treatment. Then, unless it 
fortunately turns out that the germ is still sensitive to one of 
the other related drugs, the treatment may have to be aban- 
doned and the older methods used. That is the reason, for 
instance, why serum for treating pneumonia is still used occa- 
sionally, sometimes in conjunction with the sulfa drugs, where 
a double-barrelled assault on the pneumococcus is required. 

Though in general sulfa drugs are much more harmful to the 
germs than they are to the patients, some people show abnormal 
sensitivity to them, and for that reason it is important that they 
be given by physicians, not used for self-medication. To pro- 
tect against this, in most states, laws prohibit druggists from 
selling them for human use except on a doctor's prescription. 

Even doctors have to take precautions with the sulfa group. 
They are advised, for instance, against discontinuing the drugs 
too soon. In the case of pneumonia the temperature usually falls 
to normal in 18 to 48 hours, and the pulse rate recedes soon 
after that. Other conditions connected with the disease may 
also disappear quickly with treatment, the response being so 
dramatic that all danger may soon seem past. Yet to discontinue 


the sulfa drug at this point may well result in a relapse. Author- 
ities therefore advise that the treatment continue until the pa- 
tient is completely convalescent and all signs of pneumonia are 

Discovery of the sulfa drugs and their therapeutic effect has, 
without doubt, been one of the great advances in medical sci- 
ence. But even more important than the curbing of the diseases 
they have already helped to conquer is the new technique that 
has been introduced into the healing art. Medical laboratories 
throughout the world are actively at work following these leads. 
Many of them will be blind alleys, some will lead to good re- 
sults; while a very few may even prove more valuable than 
the ones we already have, with the consequence that human 
suffering will be further relieved. 

IX. Vitamins 

An ancient Chinese physician, the Crusaders, the British 
Navy and modern American pharmaceutical laboratories; these 
are a few of the characters in the fascinating story of the vita- 
mins, those substances in our diet whose workings are not yet 
fully understood, but of which we now know enough to put 
them to effective use. With vitamins can be eliminated age-old 
diseases which occur when they are lacking. 

About 2700 B. c. the Chinese physician, Hwangti, described 
the disease we call beriberi. There is soreness and sensitiveness 
above certain nerves, numbness of the parts which they supply, 
then paralysis and swelling of the tissues. Listlessness of be- 
havior and weakness of the heart result; then comes heart fail- 
ure and death. 

The famous Greek physician, Hippocrates, also enters our 
story, for around 400 B. c. he gave the first known account of 
the disease which modern medicine calls scurvy. Civilians in 
cities under siege, seamen on long voyages, soldiers away from 
home for many months, subsisting on the food supplies they 
brought with them, suffered from it. It struck the Crusaders on 
their pilgrimages to the Holy Land. They would develop a sal- 
low complexion, feel tired and breathless. Bones were affected, 
and there was increased pain and tenderness of the body. Teeth, 
rapidly decaying, loosened and even dropped out, gums bled 
easily. Then might come hemmorhages in other parts of the 
body, and finally death. 

Fortunately for the British, in the days when their sailors 
on naval and merchant vessels were helping to build the Em- 
pire, a remedy was found. Though they had not the slightest 
conception of why the results were obtained, it was discovered 
that feeding the men fresh citrus fruits greatly lessened their 



susceptibility to scurvy. English ships carried limes for this 
purpose: thus the British sailor, and then Britons in general, 
received the appellation of "lime-juicer." 

Rickets is another disease in the vitamin story. First de- 
scribed in 1650, it undoubtedly occurred earlier. Children 
shown in fifteenth- and sixteenth-century German paintings 
sometimes display what is, to the modern medical man, an ob- 
viously rachitic appearance. Young children and infants are 
especially subject to it; bones are softened, joints enlarged, 
there may be bowlegs, and a poor deposition of lime and phos- 
phorus in the teeth and bones. 

Then also there is pellagra which, like the corn or maize 
with which it seems to be connected, is a product of the New 
World. About 1600 it was observed among the American In- 
dians, and also among Italian peasants who had used maize as 
a food. The skin on their hands, neck and feet would become 
dark and scaly, and later would redden. The alimentary tract 
became irritated, and there were also nervous and mental symp- 

The use of limes in preventing scurvy had indicated some 
connection of that disease with diet, and probably, even in past 
centuries, some clever doctors may have suspected that a per- 
son's food had something to do with the other ills. Then, in 
1881, a Swiss physiologist at Basle, N. Lunin, found as a result 
of experiments that a diet containing proper proportions of the 
then known food elements sugars, fats, proteins and minerals 
was by itself unable to support life. He concluded that milk, 
for example, "must therefore contain, besides these known 
principles, small quantities of unknown substances essential to 

In 1905, Pekelharing, in the Netherlands, reached a still 
clearer conception of the nature of vitamins when he found 
"that there is a still unknown substance in milk which even in 
very small quantities is of paramount importance in nutrition. 
If this substance is absent, the organism loses the power prop- 
erly to assimilate the well-known principal parts of food, the 


appetite is lost and, with apparent abundance, the animals die 
of want. Undoubtedly this substance occurs not only in milk 
but in all sorts of foodstuffs, both of vegetable and animal 

Not one but many substances which answer this description 
have been found in our foods. Casimir Funk, Polish biochemist 
then at the Lister Institute in London (he later came to the 
United States) published a paper in 1911 in which he sug- 
gested they be called "vitamines." This name came from "vita," 
or "life," and the chemical term "amine," the name of a class 
of compounds to which, he thought, they belonged. About 
eight years later the final "e" was dropped and since then 
"vitamin" has been commonly used. 

In order to control beriberi in their East Indian possessions, 
the Netherlands had sent out Christian Ejkman to study it. It 
was in 1897 that he concluded that the disease resulted from a 
continual diet of polished rice; and four years later his successor, 
Gerritt Grijns, showed that it was not from any poison which 
the rice contained. Rather was it caused by something the rice 
did not contain something essential in the discarded brown 
outer layer (the cortex), removed when the rice was polished. 
If the people were fed brown rice instead, they did not get 
beriberi, and even patients who had it were cured when they 
ate the unpolished grains. 

By 1914 experiments with rats had demonstrated that butter 
contained a substance which aided their growth. It was "fat- 
soluble"; that is, it would dissolve in fats or liquids, like ether 
and alcohol, in which fats are soluble. This substance is now 
called Vitamin A. But in the milk sugar which was included in 
the rat's diet, there was a second necessary ingredient, and this 
would dissolve in water. It turned out to be the same thing 
that prevents beriberi, and it was called Vitamin B. Then, it 
gradually became clear, many foods, such as citrus fruits, as- 
paragus, strawberries and tomatoes, contain still another ele- 
ment which, also water-soluble, is responsible for the prevention 
of scurvy. In 1919 this was designated Vitamin C. 


After this, the study of vitamins rapidly became more and 
more complicated. For instance, by 1925 it had been estab- 
lished that the old fat-soluble Vitamin A was double. Often it 
also contained a second fat-soluble vitamin. This proved to be 
the one which prevents rickets, and to it the letter D was as- 

Similarly, it was discovered, the B vitamin also had a mul- 
tiple character. One substance, destroyed by heat, is the one 
preventing beriberi. But in addition to this "thermolabile" (un- 
stable to heat) material there were several others which were 
thermostable (resistant to heat). Included among these was 
the one which prevents pellagra in man and a disease called 
"blacktongue" in dogs. 

American biochemists decided, in 1929, that the term Vita- 
min B should be retained for the component which heat de- 
stroyed, and to call the heat-resistant factor Vitamin G. But 
British scientists had other ideas. They preferred to retain 
Vitamin B for the entire group; then to distinguish the two 
known components as B x and B 2 , a practice later accepted by 
many Americans. But, though B! has retained its identity as 
thiamin, the original British B 2 has now been shown to be a 
mixture of several substances. 

First there comes one which aids the growth of rats and is 
called Vitamin B 2 , or riboflavin. Then there is the substance 
that prevents pellagra in man and blacktongue in dogs. In 
1938 Dr. Conrad A. Elvehjem, at the University of Wisconsin, 
demonstrated that this was nothing but a previously well- 
known chemical compound, nicotinic acid. Then there is a part 
of the heat-destroyed fraction of the original Vitamin B which 
prevents certain forms of dermatitis in rats. Chemically known 
as pyridoxin, this is also designated as Vitamin B 6 . 

Several other components have also been found in the B 2 
combination. There is pantothenic acid, discovered by Dr. 
Roger J. Williams of the University of Texas. Its lack, under 
some conditions, seems to turn gray the hair of black rats. There 
is the substance sometimes referred to as "biotin," sometimes as 


Vitamin H. Found in yeast, liver and many plant and animal 
tissues, it meets the rules for admission to the B group. That is, 
it is found in yeast, liver and cereal products; it is water-soluble, 
biologically active in small quantities, and its absence in the 
diet produces a deficiency condition. 

Speaking before a meeting of the Chicago section of the 
American Chemical Society, Dr. Elvehjem gave his hearers 
some idea of the experimental difficulties in identifying and 
synthesizing the vitamins, especially those of the B complex, 
when he said: 

The number of Vitamin B compounds left to be identified depends 
largely on the kind of animals used for experimental work. If we 
should use a cow or a sheep we might conclude that there are no B 
vitamins, since the evidence is accumulating to show that the bacteria 
in the rumen of these animals synthesize the known B vitamins. 

For example, the rumen contents of a cow may contain sixty times 
as much riboflavin as the feed which the cow consumes. The rat does 
not need nicotinic acid preformed in its diet, but the dog must be 
supplied with all the known members. Apparently the variation in 
the requirements of different species depends on the ability of the 
intestinal flora to synthesize the individual vitamins. Since the human 
has perhaps the least ability to perform such synthesis, it is essential 
that we continue our search. 

Experiments in which rats are fed with six of the factors of Vitamin 
B indicate that there are other factors. If we turn to dogs, the evidence 
is much more clear cut. 

When puppies, he explained, are put on a synthetic diet, sup- 
plemented with Vitamin B l5 riboflavin, nicotinic acid, Vitamin 
B 6 and panto thenic acid, they grow for a time, then their growth 
stops. But then, if they are fed a two-per-cent liver extract, 
growth is resumed. The liver extract can be treated so as to re- 
move, or at least to destroy, the pantothenic acid, and this still 
has a beneficial effect on growth, owing to an unknown "factor 
W." But continued feeding, either of this factor or of pure 
pantothenic acid separately, results in a failure of the dog to 
grow. When the original liver extract is given again, the dog's 
normal growth is restored. 


The vitamin with which, perhaps, most people feel concerned 
is B! thiamin. At the time the American Chemical Society 
presented him with the Willard Gibbs Medal for his researches 
on this vitamin, Dr. Robert R. Williams described it as "out- 
standing with respect to the apparent universality of its func- 
tion in living cells and the degree of dependence of the cells 
upon an adequate supply of it. The lack of no other accessory 
substance," he stated, "leads to so early, so profound and so 
universal a disaster, according to our present evidence." 

Sometimes termed the "morale vitamin," this is the one that 
is added, along with others, to "enriched" bread. The first en- 
riched bread was introduced in England; then, in 1941, Ameri- 
can bakers began its production. 

This might even be called the original vitamin, for it was the 
one Funk was studying when he proposed the name for the 
class. He tried to isolate it, and secured a crystalline substance 
capable of curing polyneuritis in pigeons. But the scientist now 
most closely identified with Vitamin B x is Dr. Williams. Evi- 
dently vitamin research is a family trait, for he is the older 
brother of the Dr. Roger J. Williams who discovered panto- 
thenic acid. 

In 1908 Dr. Robert Williams went to the Philippines and be- 
came a research chemist with the Bureau of Science in Manila, 
where he worked with Captain Edward B. Vedder of the U. S. 
Army Medical Corps. Beriberi was prevalent among the native 
troops, the Philippine Scouts, so the Army felt concerned. Dr. 
Williams and Captain Vedder knew that rice polishings could 
cure beriberi in infants, and so they attempted to concentrate 
from this source the beneficial principle. Even before Funk's 
paper had reached them they succeeded in determining some 
of the characteristics of the substance. For example, they found 
that it could pass through a membrane of parchment, that it 
was absorbed by charcoal and that a chemical called phospho- 
tungstic acid could precipitate it out of solution. 


Dr. Williams returned to the United States in 1915, and in 
1925 he became chemical director of the Bell Telephone Lab- 
oratories in New York; but his interest in vitamin study had 
continued. In 1926, in the same Java laboratory in which Eijk- 
man's original discovery had been made, B. C. P. Jansen and 
W. F. Donath announced their success in isolating this vitamin 
for the first time. 

Their technique was most delicate, and no one was able to 
duplicate their results for a number of years. Dr. Williams, 
meanwhile, was continuously at work on the problem. He im- 
proved the method, and in 1934 he and his associates were able 
to produce about five grams a little less than a fifth of an 
ounce from a ton of rice polishings. This was several times as 
good a yield as had previously been obtained; and Merck and 
Company, at Rahway, N. J., began to produce the natural 
vitamin commercially. This in turn gave Dr. Williams a plenti- 
ful supply of the pure vitamin for a study of how the atoms 
were put together. Not until the internal architecture of a 
compound is determined can the chemist put other atoms to- 
gether in the same fashion and duplicate it synthetically. 

It was in January, 1935, that Dr. Williams announced, pro- 
visionally, a structural formula for Vitamin Bj. This involved a 
complex arrangement of carbon, hydrogen, nitrogen, oxygen, 
chlorine and sulfur. In the summer of 1936 he cleared up the 
last details of its structure and made the vitamin by synthesis. 
The isolation work was accomplished in the laboratories of Co- 
lumbia University, supported with funds from the Carnegie 
Corporation. The latter part of the structural study, as well as 
the final synthesis, was carried out under Dr. Williams' direc- 
tion in the Merck laboratories. As a result, that companv and 
other manufacturing chemists soon afterwards began the com- 
mercial manufacture of Vitamin Bj in the form of thiamin hy- 
drochloride, which can now be secured at any drug store. 

Beriberi, fortunately, is a rare disease in the United States 
and Canada, but even here, as in some of the other supposedly 
"best-fed" nations, there has been a marked Vitamin B x de- 





























Like the unraveling of a rope is the untangling of the Vitamin B 
complex. This ingenious diagram, prepared by Dr. Robert R. Wil- 
liams, shows that part of the rope remains, from which scientists 
may isolate future threads. 


ficiency. This is blamed on modern methods of preparing food. 
Just as the polishing of rice eliminated the vitamin, so does 
the milling of wheat in making white flour have a similar effect. 
Dr. G. R. Cowgill has found that a diet provided in London by 
the Poor Law in 1838 actually gave twice as much E l as did 
the diet of the two highest income groups of that city in 1937. 

Proof, if it were needed, of the desirability of plenty of 
Vitamin B x in the human diet was provided by Dr. Russell M. 
Wilder of the Mayo Clinic. A group of subjects, all in good 
health, were fed a diet adequate in every way except that it 
was deficient in B!. Soon they developed mental and physical 
fatigue, moodiness, sluggishness, fear and indifference. Another 
group, receiving a diet which included an amount of the vita- 
min considered normal, practically equaling the standard set 
up by the League of Nations Technical Commission, remained 
in good health. Then he gave this group still larger amounts. 
Their capacity for work nearly doubled and their alertness was 
noticeably increased. 

Dr. William H. Sebrell, Jr., another vitamin authority, and 
a member of the U. S. Public Health Service, summarized the 
conditions existing at the end of 1940 when he told a meeting 
of the Millers National Federation: 

We have been inclined to think that the American public was a 
well-fed public. As a matter of fact, as data accumulate, we are more 
and more convinced that it is a poorly fed public, and we now have a 
lot of information to bear that out. Dietary surveys which have been 
conducted by the Department of Agriculture, widely conducted in 
the past several years, indicate very clearly that in the neighborhood 
of one-third of our entire population are receiving diets which, ac- 
cording to modern standards of nutrition, are definitely inadequate. 
Those diets are so poor that, while they supply enough calories and 
of course all our population, speaking in general terms, get enough 
calories they are deficient in minerals and vitamins to such an ex- 
tent that we see widespread symptoms of them. All groups are affected 
it is by no means confined to the low economic groups. 

In the whole wheat grain there are ample proportions not 
only of Vitamin B! but also other members of the B complex, 


as well as iron and phosphorus, minerals also needed by the 
body. In whole-wheat flour, and the bread made from it, they 
are still present, but many of us have come to prefer white 
bread. Present-day milling methods have been devised on that 
basis, and flour is made from the very parts of the wheat which 
contain the smallest percentages of the B vitamins and of the 
original mineral content. 

If everyone would start eating whole-wheat instead of white 
bread, they would have an ample supply of the grain vitamins. 
This can hardly be achieved, so the millers and bakers of the 
nation, following recommendations of the Committee on Foods 
and Nutrition of the National Research Council, are producing 
"enriched" flour and bread. Small amounts of pure thiamin, 
nicotinic acid and iron salts are added to the flour; and also, 
perhaps, as optional ingredients, riboflavin, calcium and Vita- 
min D. Bread so enriched looks and tastes no different from 
that to which we are accustomed, but nutritionists believe that 
its widespread use will be highly beneficial. 1 

In addition to all the vitamins thus far mentioned there are 
still others, some of which are quite well recognized, while 
others are suggested by certain experimental data. In the former 
class are Vitamins E and K. E, known as the anti-sterility vita- 
min, is chemically alpha-tocopherol; it is made synthetically 
and is available commercially. It is, fortunately, so widespread 
in natural foods, and so stable to ordinary methods of cooking, 
that experimenters have found it difficult to produce a de- 
ficiency in the human diet. Studies on rats and mice, however, 
indicate that such symptoms as sterility and degenerative dis- 
eases of the nervous system may result from its absence. Vita- 

1 As already remarked, such bread had been adopted even earlier in Eng- 
land, by vote of Parliament. "M. F. Flour" (Ministry of Foods flour) corrected 
dietary deficiencies which were especially dangerous in times of stress. Then, if 
ever, the people needed all possible resistance and stamina. M. F. Flour does 
not, however, contain as much Vitamin Bi as the minimum now fixed for the 
United States, and calcium is a standard, not an optional, part. 


min K is a complicated organic compound, also prepared syn- 
thetically, which plays a part in the production of a substance 
called prothrombin in the body and makes possible normal 
clotting of the blood. It also is widely distributed in ordinary 
foods, and it would be difficult to avoid getting enough in one's 

Vitamin authorities have deplored the general tendency to 
worry about each of the latest vitamins, when but a relative 
few are really important. For instance, in an address given when 
he received the Chandler Medal from Columbia University, 
Dr. Robert R. Williams said: 

I should like to divert the minds of food processors, teachers of 
nutrition, practicing physicians and laymen from speculating about 
the latest surmise of vitamin science and persuade them to devote 
their major energies to the intelligent application of the vitamins 
which stand in the front row of the shelf. 

These are six in number: Vitamin A, thiamin, riboflavin, nico- 
tinic acid, ascorbic acid (Vitamin C) and Vitamin D. The 
others, as Dr. Williams was careful to point out, cannot be said 
to play less essential roles in human physiology, for their lack 
would undoubtedly cause grave disorders. However, the chance 
of anyone whose diet is adequate failing to get ample quan- 
tities of them is so slight that this does not constitute a present 
health problem. 

Of the 'Vital vitamin" sextette, we first have Vitamin A. 
Chemically, it belongs to the class of alcohols, and it is neces- 
sary for several bodily functions. It is essential for the formation, 
in the retina of the eye, of "visual purple/' Without this sub- 
stance, vision, particularly at night and under low intensity of 
illumination, is greatly impaired. That is why Vitamin A has 
been given to night-flying aviators in order to help them see 
clearly enemy planes and other objectives. When it is lacking, 
the epithelial tissues of the body, such as those in the respira- 
tory and digestive tracts, are injured, and the eyes are inflamed. 
There may also be retarded growth and lowered resistance to 


Thin-leaved green plants used for food, such as green let- 
tuce, spinach, turnip greens, escarole and chard are, in general, 
good sources of this vitamin. Also included among foods from 
which our best supply comes are carrots, apricots and yellow 
sweet potatoes. The materials that are responsible for the yel- 
low coloring of these and other fruits and vegetables (com- 
pounds known as carotenes and cryptoxanthin ) are converted 
to Vitamin A in the body. Stable to heat, acids and alkalis, they 
survive cooking but are broken down by the action of light. 
Vitamin A is stored in the liver, so temporary shortages are 
not serious. Pregnant women and nursing mothers require more 
than the usual amount. 

Next in our list of the important vitamins comes B l5 or thia- 
min. This helps to oxidize carbohydrates, such as sugars and 
starches. Without thiamin the tissue cells are starved. This pro- 
duces injury especially to nervous tissues, so that in advanced 
cases polyneuritis or beriberi results. In milder cases there may 
be only loss of appetite, retarded growth, faulty digestion and 
nervousness. The more active a person, the more thiamin he 
needs, and, in general, men require more than women. Since 
it is essential for pregnancy and milk production, expectant and 
also nursing mothers need a particularly ample supply. It is not 
stored in the body to any extent, so it should be taken daily. 

Among the excellent sources are bran, whole or embryo 
grains, yeast, nuts, dried legumes, lean beef, lean pork, soy 
beans and dried whey. As thiamin hydrochloride, the synthetic 
form may be taken when natural sources are lacking or de- 
ficient. Enriched bread and cereals, of course, give adequate 
amounts. Since it is destroyed by heat, particularly when ac- 
companied by moisture, cooking is apt to reduce somewhat the 
potency of thiamin-containing foods. 

Riboflavin, once called Vitamin G, now is sometimes known as 
Vitamin B 2 . Perhaps it acts, along with thiamin, in the burning of 
carbohydrates. No familiar disease is caused by its lack, but 
some of the effects of such deficiency soreness of the lips and 
cracks forming at their angles have been confused with the 


effects of pellagra. Without it there is also burning and redness 
of the eyes, possibly even blindness. In the eyes of young rats 
deprived of riboflavin, cataracts are easily formed; but fortu- 
nately the symptoms caused by its lack are rare in man. 

It is widely distributed in many foods of animal as well as 
vegetable origin. Milk, green leaves of growing plants, beef 
and pig liver and kidney, mackerel and oysters are all good 
sources of riboflavin. Stable to heat, it is sensitive to light. 
Since it is soluble in water, prolonged boiling of foods may ex- 
tract the vitamin from them. However, if the water in which 
they have been boiled is used for other purposes, as in soups, 
the body will still get its supply. Prepared synthetically, ribo- 
flavin is available commercially in pure form as a light-yellow 

Next on our shelf is nicotinic acid, which was first synthesized 
in 1873, long before vitamins had been heard of. In spite of its 
name, it is not obtained from tobacco, and it is entirely differ- 
ent from nicotine, which is a deadly poison. Nevertheless, to 
allay fears of those who might believe that they were being 
poisoned by nicotinic acid in their bread, the name has been 
changed on the recommendation of the food and nutrition 
board of the National Research Council. It is now called niacin, 
or niacin amide the latter in place of nicotinamide, a form 
in which it is frequently used. It has also, in the past, been 
referred to as Vitamin P-P, the letters standing for "pellagra 
preventive" since its lack is responsible for this disease. 

It was in 1937 that Dr. Elvehjem ascertained that niacin was 
present in yeast and that it cured blacktongue in dogs. Dr. Tom 
D. Spies of the University of Cincinnati was one of the first to 
apply it to the cure of pellagra in man. Exactly what it does in 
the body is still uncertain, but a pellagra victim begins to show 
improvement very soon after taking it. The disease is prevalent 
in the South, and nutrition experts are of the opinion that it is 
best in that region to give niacin through its addition to com- 
mon foods. This is easier than persuading the people subject 
to pellagra to change their long-established food habits. Ex- 


cellent sources of niacin are bran, eggs, fish; heart, liver and 
kidneys of animals; lean meat, peanuts, wheat germ, dried whey 
and yeast. Though not affected by heat, like riboflavin it is 
soluble in water, and may be extracted from foods by prolonged 

Vitamin C, in its pure form as a white crystalline powder, 
was first isolated from lemons by Dr. Charles G. King of the 
University of Pittsburgh in 1932. The following year he made 
it synthetically. About the same time it was independently pre- 
pared by Dr. Albert von Szent-Gyorgi from the paprika of his 
native Hungary, and it was he who named it ascorbic acid. 
This work won for him the 1937 Nobel Prize in Medicine. 

In the body, ascorbic acid seems to be needed in the manu- 
facture of "cement substance," responsible for holding together 
the cells of bone, teeth and connective tissue, as well as tis- 
sues generally. Loss of appetite, fatigue, anemia and weakness 
may appear when it is deficient. If the condition continues, 
scurvy develops. As with other vitamins, nursing and expectant 
mothers need more (about twice as much) as other adults. 

Lemons, oranges, grapefruit and limes are excellent sources 
of ascorbic acid, but oxygen in the air quickly destroys it. Thus, 
the potency of the juices of citrus fruits is soon lowered if they 
are allowed to stand. For this reason orange juice should be 
squeezed from the fruit immediately before it is used. Beet 
greens, broccoli, cabbage, cauliflower, green and red peppers, 
tomatoes, strawberries, spinach, green peas and liver are also 
excellent sources. However, the ease with which the vitamin 
is destroyed not only by the air but also in cooking means that 
the sources should be used fresh and raw wherever possible. If 
an adequate supply from food is not available, pure ascorbic 
acid may be taken. 

Vitamin C also promises to be an important aid in the pre- 
vention of heat prostration among industrial workers and others 
who are exposed to the effects of high temperature and hu- 
midity. A few years ago a South African physiologist found that 
native Bantus, working in the gold mines of the Witwatersrand, 


frequently contracted scurvy, although their diet contained 
adequate amounts of ascorbic acid. Tests proved that most of it 
was lost, before it did any good, in the perspiration which was 
most profuse under the hot humid conditions existing in the 

In the summer of 1939, at one of the Du Pont cellophane and 
rayon plants in the South, a group of men had to make an 
emergency repair above a hot drying cabinet. For several weeks, 
while they were doing this job, they were exposed to tempera- 
tures well above 100 Fahrenheit. Previously, when at such a 
task, each man would take a salt pill every time he took a 
drink of water. This has long been a standard practice, as much 
of the body's salt is lost through perspiration, and there may be 
ill effects if it is not replaced. In spite of this, however, a num- 
ber of the workers had suffered heat cramps and heat pros- 

On this occasion Dr. W. L. Weaver, head of the plant's medi- 
cal unit, had the men take Vitamin C in addition to the salt. 
At morning and at night they received 50 milligrams. The to- 
tal amount, 100 milligrams, is well above the normal daily 
requirement. During the course of the job not a man suffered 
from heat cramps or collapse. Except for one man (who had 
been drinking over the week end) they did not even show any 
variation in blood pressure, which is a sign of incipient heat 

As a result of this experience all the employees of the plant 
have been given daily doses of vitamins, including not only C 
but Bj as well, since this also is known to be lost in the perspira- 
tion. Almost no cases of heat cramps or exhaustion have oc- 
curred since, though formerly the dispensary had four or five 
cases a day in hot weather. 

The part played by Vitamin B 3 in connection with heat ef- 
fects is not very well understood, but Vitamin C is believed to 
be associated with the action of the muscles. Even when our 
bodies are still, our muscles are continually contracting. This 
is called muscle tone, and is important, along with the usual 


muscular activity in movement, in pushing blood through the 
veins back to the heart. Vitamin C, it seems, helps maintain 
muscle tone. Said Dr. John H. Foulger, director of the Du Pont 
Company's Haskell Laboratory of Industrial Toxicology, in a 
report on this work which he gave the Millbank Memorial 

In heat prostration the muscle tone is diminished. Likewise the 
blood vessels of the skin are dilated in an effort to pipe greater 
amounts of the heat-laden blood to the surface where it can be cooled. 
This leaves less blood in the large internal vessels, gives the heart less 
to pump against and further adds to the collapsed state of the circula- 
tion. These two factors, the necessity for the muscles to push the 
blood up to the heart against the force of gravity, and the dilation of 
the peripheral vessels in hot weather, are principal reasons why peo- 
ple often faint while standing to watch a parade in the summer time, 
or why soldiers sometimes faint when standing for long periods at 
attention. In both cases the muscles are fairly inactive. Vitamin C 
prevents this, we believe, by maintaining the muscle tone both in the 
large muscles and in the small ones of the walls of the arteries and 
their branches. 

Thus it would seem that lemonade, if it is strong enough, has 
a beneficial effect in hot weather aside from its relief of thirst. 2 

In Vitamin D we have a very different state of affairs from 
that of the others mentioned. Vitamin D is not a single chemical 
substance; but probably more than a dozen different com- 
pounds, belonging to the class of "sterols," can be made to show 
its properties. Chief of these is that, in the body, it aids absorp- 
tion of calcium and phosphorus from the intestines. It maintains 
the proper amount and form of these elements in the blood 
thus the growth of bones and teeth is assisted. Rickets, which 
is a failure of the body to deposit calcium and phosphorus in 
the bones of children, and osteomalacia, a comparable disease 

2 Ths treatment is directed against heat exhaustion, not heat stroke or sun 
stroke. In heat exhaustion or heat prostration, which is more common than the 
stroke, the patient is usually conscious. He is covered with cold sweat, breathing 
is shallow and rapid and the pulse is rapid and feeble. Heat stroke, on the other 
hand, is indicated by dry, hot skin and flushed face, while the victim is always 


of adults in which the bones soften and break easily, result 
from the lack of an ample Vitamin D supply. 

Studies of this vitamin have given some justification to the 
sun worshipers. Unlike the others, which are taken into the 
body in some solid or liquid form, Vitamin D can be obtained 
by exposure to the ultraviolet rays of sunlight or in the radia- 
tion of a sunlamp. There is in the body a material called 
cholesterol, and these invisible rays confer upon it the bene- 
ficial qualities of the vitamin. Some animals are covered with 
much hair that prevents the sun's rays from reaching their skin. 
In their hair is a compound similar to cholesterol; this also is 
activated by the ultraviolet light; then, as the animal licks it- 
self, the vitamin is taken into the body. 

Dr. Harry Steenbock, of the University of Wisconsin, in- 
vented a process by which artificially produced ultraviolet rays 
may be used to irradiate many foods, such as milk, and give 
them the beneficial properties of Vitamin D. Ergosterol, an- 
other member of the sterol family, is similarly irradiated then 
it is called "viosterol" and used as a source of the vitamin which 
can be taken in a convenient form. Bombardment by the tiny 
particles called electrons also is able to activate these sub- 

Among the relatively few foods which normally contain Vita- 
min D are salmon, tuna, herring, sardines, egg yolk, cheese, 
butter and chocolate. Even more fully provided with the anti- 
rachitic properties is halibut liver oil, probaby the best natural 
source, and cod liver oil, to a lesser degree. Sunlight, however, 
is the best way of providing its protection. And, once more, 
nursing mothers and pregnant women have particular need of 
its qualities. 

Departing now from these fields of vitamin study where 
knowledge is fairly well established, we find on the frontiers 
many new and apparently unrelated data which future work- 


ers will have to correlate. Some of these, interesting to every- 
one because they concern one of the more obvious effects of 
aging, bear upon the influence of vitamins on the graying of 

A few years ago it was found that pantothenic acid, given in 
daily doses from infancy, seemed to prevent the hair of black 
rats from turning gray. If the diet of the rats was deficient, 
and their hair did turn gray, the black was restored when this 
vitamin was given. The reaction of rats to food is in many re- 
spects similar to that of man, and they have helped to reveal a 
large part of our knowledge of the action of vitamins and other 
food elements. Consequently there seemed to be some hope 
that these findings might be applied to human beings. How- 
ever, Dr. Robert Williams repeated the rat experiments, only 
to find that, under his conditions, "neither pantothenic acid 
concentrates nor pure pantothenic acid exhibited a preventive 
or curative effect on the gray hair of rats, although the rate of 
growth and the length of life were greatly enhanced." 

Then, at a meeting of the American Chemical Society in 
1941, Dr. Gustav J. Martin, of the Warner Institute for Thera- 
peutic Research, and S. Ansbacher, of the International Vita- 
min Corporation, reported that another B vitamin, para-amino- 
benzoic acid, seemed to accomplish the desired results in man. 
Giving small daily doses to thirty patients, they found a marked 
darkening of hair already turned gray along with a growth of 
new, naturally colored hair. Similar results were obtained by 
others, but, on the other hand, para-aminobenzoic acid did not 
seem to produce any effect on rats. 

Then also inositol, another member of the B complex, seems 
to have a role. In experiments by Dr. D. W. Wooley at the 
Rockefeller Institute it was found to prevent baldness, provided 
it was given in conjunction with the para-aminobenzoic acid. 
When the experimental animals were given the acid but no 
inositol, they became bald. And early in 1942, to the American 
Institute of Nutrition, Dr. Martin reported that lack of the acid 


resulted in gray hair in animals only when pantothenic acid 
and inositol were fed in effective quantities. That is, a lack of 
all three did not produce the gray hair. 

At this same meeting, Dr. Ansbacher told of experiments in 
collaboration with Dr. Martin and Dr. W. A. Wisansky, of the 
American Home Products Corporation. Their subjects were 
thirty gray-haired persons who were under just as close control 
as laboratory animals they were inmates of a prison. Each 
day for eight months they were given 100-milligram para- 
aminobenzoic acid tablets. At the end of the period more than 
two-thirds of the men had the original color of their hair at 
least partially restored. 

Because of the conflicting results in this fascinating field, 
there is no doubt that the complete answer is yet to be found. 
Perhaps, however, it is no worse than was the position in re- 
gard to beriberi in 1910. Modern workers have as a guide the 
past studies which the vitamin pioneers lacked, so it is not too 
much to hope that a correct answer may be found. Not only 
gray hair and baldness, but also other concomitants of old age 
may similarly be alleviated with vitamins. Then, with the aid 
of other medical advances, science may have made an approach 
to achieving that fountain of youth which Ponce de Leon vainly 

X. New Metals 

With the use of metals going back to the dawn of human 
history, it may, perhaps, seem surprising to speak of "new" ones. 
About 60 of the 92 known chemical elements are metals. These 
have always existed, though man may not have discovered them 
until recent times. Many of them did not exist in their metal- 
lic form until it was found how to extract them from the com- 
pounds, the "ores" in which they occur in nature. And even 
aside from these, there are "new" metals. They are the alloys, 
mixtures of two or more other metals, which metallurgists have 
fashioned with startling results; for they have a range of prop- 
erties far greater than those of the metals of which they are 
made. Some are hard, some are soft. Some can be magnetized 
most strongly, others are as little affected by magnetism as 
wood. Some are twice as dense as iron, while others are nearly 
light enough to float on water. Without their development, our 
civilization would be very different. There would be none of 
the high-speed trains or powerful automobiles to which we are 
used, no modern airplanes, no inexpensive and efficient electric 
lamps or radio tubes. 

Copper occurs free in nature; it was the first metal to be 
used by early man, since it is soft enough to be hammered 
easily into the shape of the tools that he desired. Then it was 
refined from ores, particularly copper oxides, from which the 
metal could be extracted easily. This all started before the be- 
ginning of historical records; and next, it is conjectured, some 
ingenious primitive metallurgist found that a small amount of 
tin mixed with copper made its strength much greater than 
either of the original two metals. This mixture is bronze, the 
first alloy to be made by man, though it may not have been 
the first he used. 



Long before life appeared on the earth, nature had been 
bombarding our planet with pieces of an alloy of iron and nickel 
in the form of meteorites. Many millions of meteors enter 
the earth's atmosphere daily, though seldom is one sufficiently 
big to survive the heating it receives in that passage. But when 
it does, and lands on the earth, then it is a meteorite. Without 
much question, primitive men found such pieces of metal and 
made use of them. The supply of this natural iron alloy was 
severely limited, and bronze was the first alloy to be widely 
employed. In the development of many cultures, archaeologists 
recognize the Bronze Age as an important period, following an 
age when stone weapons and tools were used. Peoples of Eu- 
rope, Egypt, much of Asia, and even parts of Central America 
passed through a Bronze Age, and many beautiful relics of 
their work survive in museums. Brass, which is an alloy of cop- 
per with zinc instead of tin, came later. Probably where brass 
is mentioned in the Bible, really bronze was meant, for the 
two terms have often been used rather loosely. 

Following the Bronze Age, in most cultural developments, 
came the Iron Age. Perhaps this began with the working of 
meteoric iron, or else accidentally when the metal was found 
in the ashes of a large fire that, so it happened, had been built 
against a bank of an iron-containing ore. Its usefulness dis- 
covered, the obvious step would be to build such fires de- 
liberately, then to enclose them, making primitive blast fur- 
naces. Like the use of glass, then, the art of working with metals 
and alloys is an old one. But, again like glass, modern technical 
developments have vastly increased their use. Some of these 
improvements have been in refining methods for example, the 
process by which aluminum could be made so cheaply that, in 
times of peace, it could be used in the ordinary household for 
pots and pans. 

Of all metals, aluminum is most abundant in the earth's 
crust, but it never occurs in metallic form. Always it is in a 
compound, frequently of silicon and oxygen; that is, a silicate. 
Another common ore is bauxite, an impure oxide. There is 









(see page 153) 


(see page 158) 


t T-C 



(see page 160) 


(see page 181) 


(see pages 181-182) 




some uncertainty over who first actually isolated the metal. 
The Danish chemist, Hans Christian Oersted, in 1825 an- 
nounced to the Royal Danish Academy of Sciences that he had 
obtained it, though this has been questioned, and the credit 
is customarily given to Friederich Wohler, who, though unable 
to obtain it by repeating Oersted's experiments, did secure it by 
another process in 1827. 

By 1855 a French chemist, Henri Sainte-Claire Deville, was 
able to exhibit a bar of the metal at the Paris Exposition. The 
Emperor Napoleon III heard of this, and realized how valua- 
ble aluminum would be for making light-weight equipment for 
his soldiers, to increase the army's mobility. Accordingly, with 
imperial backing, Sainte-Claire Deville set to work producing 
it commercially. Whereas it had been worth $545 per pound in 
1852, by 1856 Deville managed to bring it down to $35, and 
to $17 in 1859 when the world production was just two tons. 
Though this was not cheap enough to permit the widespread 
use that Louis Napoleon had envisioned, at least it made the 
metal available to scientists; and they began to recognize its 
potential usefulness. 

In 1886 two young men, each 22 years old, independently 
discovered a cheap way of preparing the metal. In the United 
States it was Charles M. Hall, who had been graduated from 
Oberlin College nine months earlier, and in France it was Paul 
L. T. Heroult. The effect of their discoveries is shown by a 
comparison of the 17.6 tons which was the world production 
in 1886 with the 715,000 tons the world produced in 1939, a 
figure surpassed only by iron, copper, lead and zinc. The cost 
in the latter year was about 20 cents a pound. 

Young Hall's discovery was no accident, but the result of a 
definite search. One of his professors had told him that the man 
who could perfect an inexpensive method of extracting alumi- 
num from the vast stores of its compounds which lay in the sur- 
face of the earth would be a benefactor to mankind and would 
make a fortune in the bargain. So, with youthful confidence, 
Hall set out to do it. 


The process he discovered after nine months, working in his 
father's woodshed, started with the melting of cryolite, which 
is a mineral containing aluminum that is obtained from Green- 
land. It melts to a clear liquid at about 1000 Centigrade; and 
then aluminum oxide, otherwise called alumina, will dissolve 
in it. Hall passed an electric current through such a molten 
bath; the alumina was separated into its parts. Oxygen was 
given off and buttons of aluminum metal settled at the bottom. 
Thus, Hall's confidence that he could solve this old problem 
was justified. 

Bauxite is the chief aluminum ore, and though it is aluminum 
oxide, it has to be purified to prepare it for the Hall-Heroult 
furnace. The furnace in its present form consists of an iron box, 
lined with blocks of carbon which serve as one electrode ( the 
cathode), while the other electrode is a series of plates of car- 
bon which are lowered into the box. When these are touched to 
the carbon lining and current is connected, an electric arc is 
formed, and this melts the cryolite as it is added. ( Incidentally, 
we are not necessarily dependent on imports for the cryolite, 
which can be prepared artificially. ) It is melted by the current 
and then the alumina is introduced. In modern furnaces molten 
aluminum flows out through a hole in the bottom, to be cast 
into ingots, ready for whatever use is desired. 

To make a pound of aluminum requires four pounds of baux- 
ite which, when purified, makes two pounds of alumina. In 
refining one pound 12 kilowatt hours of electricity, enough to 
supply an ordinary home for several days, is consumed, along 
with three-quarters of a pound of carbon in the electrode. Some 
of the supply of bauxite comes from Arkansas, but much of it 
is imported from Surinam (Netherlands Guiana). Getting the 
enormous quantities of electric power needed for the produc- 
tion of billions of pounds of aluminum is also a problem, but 
one which the recent hydroelectric developments on the Co- 
lumbia River will help to solve. 

To meet the shortage of bauxite, other processes have been 
developed. One, for instance, uses as the ore alunite, a reddish 


mineral found in Utah and other Western states. Another 
process, developed at Columbia University by Dr. Arthur W. 
Hixson, starts with clay and other ores having a high silica con- 
tent, which are found in great abundance in many parts of the 
country. Advances in synthetic plastics and ceramic ware, and 
improved methods of handling rubber, among other items, have 
made it possible to use hydrochloric acid in this process, which 
eliminates some previous difficulties. It produces aluminum 
chloride, which is then converted to alumina and refined by 
the usual method. 

Shortly before World War I, Alfred Wilm, in Germany, dis- 
covered that an alloy made of aluminum with four per cent 
copper, one-half per cent magnesium, and one-half per cent 
manganese could be heated, cooled by quenching in water and 
aged several days to make a metal strong as steel, yet retain- 
ing practically all the lightness of aluminum. This was called 
duralumin, and it was employed in the Zeppelins. Modifications 
of this alloy are used today in most of the world's fighting 

Aluminum alloys, like many others, are subject to corrosion, 
with consequent weakening and possible failure of structures 
made from them. But in most cases very pure metals are re- 
sistant to corrosives, and this is true of aluminum. So the Na- 
tional Bureau of Standards made a suggestion, which was ap- 
plied by the Aluminum Company of America's metallurgists, 
of coating the strong-alloy sheets with the pure metal; and this 
has proven of great value, especially in all-metal planes, where 
aluminum makes up more than three-fourths of the weight. 

The advantage of aluminum's lightness for airplanes is one 
that can readily be appreciated, since the less the craft weighs, 
the more can be lifted off the ground as useful load in the form 
of fuel for long-range flights, passengers or bombs. But this 
same lightness is advantageous elsewhere. Most states have 


laws limiting the gross weight of trucks on their highways, so, 
if the truck itself weighs less, the load can be greater yet stay 
within the requirements. Accordingly, aluminum has been used 
for truck bodies. Even in static structures, light weight is of 
value. In a long bridge, as much as 80 per cent of the total 
weight may be required just to sustain itself. If the structure is 
lightened by using aluminum for the flooring, that much addi- 
tional live load may be carried. 

Even lighter, by approximately a third, than aluminum is 
magnesium, which burns with an intensely white light and for- 
merly was used by photographers in flashlight powder. Larger 
pieces, however, are difficult to start burning; thus the metal 
can be handled and worked. Even so, high enough tempera- 
tures will start ignition the principle by which magnesium is 
used in incendiary bombs. In the bomb is a thermit mixture, 
of iron oxide and aluminum, which burns with great heat; its 
main use is normally for welding. In the bomb, it easily gen- 
erates sufficient heat to start the magnesium. 

In construction work, magnesium is never used alone, but al- 
ways as an alloy. These alloys, usually with aluminum, are 
known as Dowmetals, after the Dow Chemical Company, 
principal producers in the United States of magnesium, which 
introduced them. A typical alloy of this type, known as Dow- 
metal A, contains 92 per cent magnesium and eight per cent 
aluminum, which is many times harder and stronger than mag- 
nesium alone. This alloy has the advantage of being highly 
resistant to corrosion. 

The Dow Chemical Company entered the magnesium-metal 
field as a result of World War I; and thanks to their pioneer- 
ing, we had the nucleus of a large productive capacity when 
we entered World War II. In 1914 Dow was producing and 
marketing magnesium chloride and calcium chloride, used in 
cements at that time. The magnesium salt had been imported 
from Germany, but when this was no longer available Dow 
started producing it. The source is the great subterranean salt 
lake which underlies part of Michigan between Lake Huron 


and Lake Michigan. The brine from this lake is pumped to the 
surface, and more than 300 useful products are made from it. 
It was experience with this brine that gave the Dow chemists 
the background to enable them to mine the ocean itself for 
magnesium, and also for bromine, used in making ethyl gaso- 
line. 1 

But still the most important of our metals is that same one 
which was used thousands of years ago in Egypt, and which 
makes up almost a twentieth of the earth's crust. This is iron, 
and fortunately the United States is amply provided with its 
ore, largely of iron oxides, similar in its red color as well as its 
chemical makeup to the rust which forms on iron when exposed 
to the air. Iron is strong when mixed with carbon; steel is the 
result. It can be hardened by quenching that is, heating it and 
suddenly cooling it by plunging the piece into a liquid such as 
water or oil. Since steel, as well as iron, is subject to corrosion 
in its ordinary form, in recent years increasingly large quan- 
tities of "stainless steel," developed by metallurgical research 
in the United States, in England and in Germany, have come into 

Chromium is the secret of stainless steel, and to deserve the 
title an alloy must contain at least 12 per cent of this metal. 
Some contain as much as 25-30 per cent, though these are used 
more for resistance to heat than to corrosion. 

Cutlery was the first application of stainless steel to have wide 
use, as the result of the work of an English metallurgist, Harry 
Brearley. Studying steel alloys that might be used to line rifle 
barrels, he happened in 1912 to make one containing 12.8 per 
cent of chromium with the iron. When samples were sent to the 
laboratory for examination, it was found that they were very 
difficult to etch with nitric acid. Brearley realized the value of 

1 However, there are also other sources of magnesium, and a plant has been 
erected with government aid in California to make magnesium from magnesite, 
a mineral found in Nevada. 


such a steel for cutlery, since it would not be affected by acids 
in foods; but at first he had difficulty in interesting the manu- 
facturers. In 1914, however, they began to use it for knives. 

About the same time F. M. Becket, in the United States, was 
interested in finding an alloy that would withstand tempera- 
tures up to about 2000 Fahrenheit without oxidizing. He 
found that 20 per cent or more of chromium with the iron gave 
excellent resistance. 

Also seeking a heat-resistant metal were two German scien- 
tists, Benno Strauss and Eduard Maurer, of the Krupp Works. 
As early as 1910 they had prepared alloys with 20 per cent of 
chromium; and they found that these remained bright while 
others, even with a quarter nickel, became rusty when exposed 
for some time to the air of the laboratory. Then they experi- 
mented with the resistance of metals to corrosion by fresh and 
sea water, and tested alloys not alone of chromium but also of 
nickel and chromium with iron. From this work came "18-8," 
which consists of 18 per cent chromium, eight per cent nickel 
and the balance iron, today the most popular of the stainless 
steels. 2 

Denser than aluminum, stainless steel weighs more than that 
metal, volume for volume. But because it exceeds aluminum in 
strength, in many cases less stainless steel need be used. Con- 
sequently, for comparable weights, the two metals compare 
favorably in strength. 

2 In 1940, 276,698 tons of stainless steels were produced in the United States, 
as compared with 59,270 tons in 1930. Nearly 45 per cent of the 1940 figure 
was "18-8." The greater part went to the automobile industry, which used it 
for trim and corrosion-resistant outside work on cars. Patents were applied for 
in October, 1912, by the Krupp Company, and they were granted in the United 
States as well as in Germany and other countries. After we entered World War I, 
the American patents were confiscated by the Alien Property Custodian and 
made available freely for the use of the Allies. After the War they were turned 
over to the Chemical Foundation, which profited by the license fees for their 
use. Thus the Foundation was able to do a valuable task in aiding research, 
and also in popularizing the findings of the chemists. It was on the basis of 
these patents that extensive American production was begun by the Allegheny 
Ludlum Steel Corporation, and later by the U. S. Steel Corporation, the Crucible 
Steel Corporation, and others. 


Other metals are alloyed with iron in the various kinds of 
steel manganese, for example, gives great strength and resist- 
ance to cutting, so it is used for jail bars. But all steel manu- 
facture makes use of small amounts of manganese. About 14 
pounds of the metal, in combination with iron, go into every 
ton of steel that is made. One reason is that it takes care of 
the sulfur that is present in practically all iron, and which can 
be removed only at considerable expense. Without manganese, 
the sulfur unites with the iron chemically, forms an iron sulfide 
at the boundaries of the metal grains, and causes weakening of 
the structure. Since Russia, Turkey and the African Gold Coast 
have been the main sources of this metal, for which no sub- 
stitute has been found, our government is vitally interested in 

In tungsten we have a metal that is not only the source of 
much of the world's illumination in the Mazda lamp; when 
alloyed with iron it also does most of the cutting of other metals 
in the lathes, milling machines, planers and shapers of America's 
machine shops. This development was brought about by El- 
wood Haynes, automotive pioneer who had made experiments 
with combinations of nickel, cobalt and chromium as early as 
1895. From 1907 to 1913 Haynes was searching for durable 
spark-plug electrodes. Cobalt, chromium and tungsten alloys, 
in which iron was present, if at all, only as an impurity, proved 
the best, and were known as Stellite. It is used today for cut- 
ting tools, along with other alloys of tungsten with iron. 

Steel containing tungsten is hard and tough, and, even more 
important, it retains these qualities when hot. Thus it is pos- 
sible to run machines so fast that the tungsten-steel tools used 
for cutting edges actually heat to redness without dulling. And 
the faster the machines can be run, the more production may 
be speeded. Even better than tungsten steel is a compound of 
tungsten and carbon, sometimes with titanium as well, which 
is called Carboloy. Invented at the Krupp Works in Germany, 
it was developed in the United States by the General Electric 


Company. Tools of Carboloy can be run still hotter, up to as 
much as 1500 Fahrenheit, thus further accelerating produc- 
tion rates. 

China and Burma have been the chief sources of tungsten in 
the past, but some deposits of its ores have been found in the 
Western states, particularly California, Nevada and Arizona. 
In searching for the ore, prospectors often work by night and 
take advantage of the same '^lack" light that makes possible 
modern fluorescent lamps. Scheelite, one tungsten ore, is cal- 
cium tungstate, a fluorescent mineral. That is, when invisible 
ultraviolet rays fall on a piece, it gives them back in the form 
of visible light. For the use of the prospectors, a portable bat- 
tery-operated ultraviolet lamp has been developed. The pros- 
pector carries this into the field, and shines his lamp on the 
places where he suspects tungsten may be found. If scheelite is 
present, it glows with a greenish color. 

Fortunately there is a substitute for tungsten in some cut- 
ting tools molybdenum, a heavy metal of which the United 
States possesses nine-tenths of the world's supply. And two- 
thirds of this comes from a single location in the mountains of 
Colorado. In addition to its use in tools, "moly," as it is fa- 
miliarly called, is alloyed with steel for other purposes. Mo- 
lybdenum steel has little "creep," which is a slow flowing of the 
metal under strain when it is hot. 

That oldest of metals used by man copper still retains its 
important place. Its alloys in the form of the various bronzes 
and brasses, and with nickel in the form of Monel metal widely 
used in chemical industry, take a large proportion of the pro- 
duction of copper. Luckily this metal is plentifully found in the 
United States, as at the Leonard mine of the Anaconda Copper 
Company, half a mile or more below Butte, Montana; or the 
open-pit mine at Bingham, Utah, where the ore, though of 
relatively low grade, is so easily accessible that it need just be 


scooped up from the surface. And in Arizona there is the similar 
Morenci mine of the Phelps-Dodge Corporation. 

To recover all the copper from these ores some surprising 
methods are used, one of which is the seemingly magical way 
in which old pieces of iron are apparently changed to copper. 
According to the story, some years ago a man named Jim Lefad 
lived in a Montana town near a copper mine, and a stream of 
waste water from the mine flowed through his back yard. One 
day he threw into this stream some "tin" cans. (Actually these 
are 98 per cent or more of sheet iron, with only a coating of 
tin. ) Next day Jim found, in place of the cans, a sludge which 
proved to be about 98 per cent pure copper. Contracting with 
the mine for all their water, he applied the process and re- 
covered $90,000 worth of copper the first year. 

This process is now used at Butte and at other mines. Old 
rails, parts of automobiles, any kind of scrap iron is used, and 
even new iron has been employed. What happens is due to the 
fact that the drainage of the mines is rich in copper sulfate, or 
"blue vitriol"; but the group of sulfur and oxygen atoms forming 
the sulfate part of the compound prefers to unite with iron 
when it can do so. Thus, when this metal is provided, iron 
sulfate is formed and metallic copper remains. Copper sulfate 
makes the mine water blue; but it becomes yellow, from the 
iron salt, after the reaction has occurred. 

In three plants in the Southwest, planned by the Defense 
Plants Corporation, old tin cans collected from towns in the 
neighborhood will be cleaned and shredded for use at the cop- 
per mines. A pound of copper takes the place of about the same 
weight of iron; so this process will add materially to the na- 
tion's copper production, but without the expenditure of other 
forms of scrap iron, which might have better uses. In some parts 
of the country, de-tinning plants are in operation to recover 
the small percentage of tin from the cans. But they cannot ex- 
tract it all. The slight amount of tin remaining in the iron ruins 
it for most other applications, though not for the copper process. 


Most operations on metal produce a certain amount of scrap, 
such as the shavings given off when steel is machined in a lathe. 
While in many cases scrap of this sort can be used, processes 
which consume all the metal without any waste are, in general, 
to be preferred. And that is one of the advantages of the new 
process of "powder metallurgy/' which is making rapid ad- 
vances for the fabrication of small metal parts, and mav even- 
tually be used for much larger ones as adequate machinery is 

This method is comparable to pill making; and some of the 
tools used are indeed simply modified pill machines. With 
powdered metal taking the place of the powdered drugs used 
for the pills, the machine exerts a pressure of from five to 100 
tons per square inch and compacts the powder into a solid 
mass. By varying the dies used in the press, the "pills" may be 
made in any shape desired; that of a small gear, or perhaps an 
electrical contact or a commutator segment for an electric mo- 

For a pill this suffices; but the metal mass, while strong 
enough to be handled, can still be broken by hand. It is neces- 
sary to sinter that is, to bake it for periods ranging from a 
few minutes to many hours. Temperatures used are well below 
the melting points of the metals, yet in some way the heat fastens 
the powder particles tightly together. The part shrinks in the 
sintering as much as 20 per cent. This shrinkage can, however, 
be accurately controlled, and parts be made large enough in 
the press so that when shrunk they are within a few thousandths 
of an inch of the correct size. 

The great advantage of powder metallurgy is that it yields in 
a single process parts which do not require time-consuming 
machining to give them exact dimensions. This can only be 
done, however, if the shapes are not too complicated; for the 
metal powder refuses to flow around a corner, and all parts of 


the shape must be directly in line with the jaws of the dies. 3 
With powder metallurgy materials as different as copper and 
graphite may be combined. And the products may be made 
either dense and solid, or highly porous, a somewhat unusual 
state for a metal. Bearings are made of this spongy material. 
They soak up oil and distribute it uniformly over the bearing 
surface. They can take up so much oil that they form an oil-less 
bearing which can be sealed into a machine, such as an electric 
refrigerator, and forgotten. Filters can be made in the same 
way. One, about as large as a thimble, is used for filtering the 
oil for Diesel engines; it can handle several gallons a minute. 


Similar processes are also used in making permanent magnets 
out of the alloys called "Alnico," consisting of aluminum, nickel 
and cobalt, in addition to iron. Magnets have numerous appli- 
cations, especially in electrical meters, such as the watt-hour 
meter in your cellar that measures your use of electricity. They 
are also important items in loud speakers for radios. 

Until about 1930 the most potent permanent magnets were 
made of alloy carbon steel; then alloys free from carbon were 
devised, and the Alnicos are among the most effective. Five 
principal types of Alnico are now available, as the result of 
further development by General Electric scientists. Some of 
these alloys are made into magnets by casting melted metal in 
a mold; but in smaller sizes, such as the one used as a control 
for electric refrigerators, the most economical method is by 

8 Like so many useful methods, the idea of powder metallurgy is an old one. 
It goes back to 1829 when William H. Wollaston, in England, used it to work 
platinum, which, melting at 3224 Fahrenheit, could not be fused in the fur- 
naces then available. However, Wollaston made fine platinum wires with the 
powder method. Its first modern use came in 1910 when Dr. W. D. Coolidge, in 
the General Electric Research Laboratory, found that it was the only practical 
way to handle tungsten, which melts at 6100 Fahrenheit, in preparing the 
wires for the Mazda lamp. Thus treated, and made ductile, tungsten could 
be drawn through diamond dies into the fine filaments which these lamps re- 


pressing from powder and then sintering. After that, the piece 
is magnetized by exposing it to an electromagnetic field. 

The theory of magnetization is that the metal is made up of 
myriads of tiny magnetic "domains," each one of which, in turn, 
consists of a vast number of atoms. These domains are perma- 
nent magnets of microscopic size, but in the unmagnetized 
metal they have various directions and neutralize each other. 
In a piece of soft iron, which becomes magnetic while inside a 
coil carrying an electric current, they turn around and line up 
parallel to the magnetic field of the coil; but as soon as the 
current is turned off, they resume their original directions. In 
a permanent magnet, instead, they remain lined up even after 
the electromagnetic field is removed. 

The latest type of Alnico is about thirty times better than the 
best carbon steel formerly used. This means that the magnet 
can be made smaller and still have the same pull, wherefore the 
apparatus using it can be made more compact. Another ad- 
vantage is its resistance to heat and vibration, which quickly 
demagnetize the older materials. 

Perhaps the most easily understood means of comparing 
magnets ( though it is open to objections from a technical stand- 
point) is in terms of lifting power. As children we may have 
played with a horseshoe magnet, which for some reason was 
usually painted red. This was probably made of carbon steel, 
and if a half-pound magnet could support its own weight, we 
thought it pretty good. When chromium was added to the steel 
used for the purpose there was a slight improvement, and more 
came with the use of a tungsten steel. Then a great advance 
came about 1923, when Honda, a Japanese metallurgist, intro- 
duced steels containing cobalt and it became possible for a 
simple half-pound magnet to lift twice its own weight, or more. 
Aluminum and nickel were then added as well as cobalt, to 
produce Alnico, and one type (Alnico II) is strong enough to 
permit a half-pound magnet to lift nearly two and a half 

The next great advance came with the discovery that the 


alloy could be heated and then slowly cooled in the field of a 
powerful electromagnet, This product is called Alnico V; and 
while it contains considerably more cobalt than its predecessors, 
making the cost per pound higher, it is so much more powerful 
that a much smaller magnet will do the same work. Thus its 
cost per unit of energy is about the same. A half-pound Alnico 
V magnet will lift a bar of iron weighing nine pounds. 

In smaller sizes, and with the magnets of special shape and 
weighing perhaps a fraction of an ounce, this ratio can be 
greatly increased and a magnet made to lift as much as 500 
times its own weight. And from here on, still more increase can 
be secured with special assemblies. The record seems to be held 
with one devised by Goodwin H. Howe, a Schenectady metal- 
lurgist, which can lift and hold nearly 4500 times its own 
weight, enabling a magnet weighing three-fourths of an ounce 
to support as much as 200 pounds in tests. 

A bar of any magnetic material, when magnetized in the 
normal way, has two "poles"; and when the bar is hung by a 
thread tied at the center, it tends to line up with the magnetic 
field of the earth. One pole seeks the north, the other the south. 
But a much more complicated type of magnet is possible with 
Alnico, for a bar can be given a second set of poles in the center. 
An Alnico disc can be magnetized with two, four, six or more 
poles around its edge; and this offers the possibility, which has 
been realized experimentally, of a train of magnetic gears with- 
out any teeth. If the discs are mounted, like little wheels, close 
to each other but not touching, one can be turned and the 
adjacent ones will follow, since unlike poles attract. The north- 
seeking poles of one disc then will pull on the south poles of the 
next, thus dragging the other disc around. 

Unlike poles attract, but like poles repel each other. How- 
ever, it was not until the development of these modern alloys 
that it became possible to make magnets so strong that one 
could support another in space above it by repulsion. Now an 
interesting application of this effect to the working of artificial 
teeth has been made by a New York dentist, Dr. Hyman 


Freedman, using an alloy containing titanium designed for 
maximum permanence and repelling power. 

Plates of artificial teeth are held in place by suction. No 
trouble is ordinarily experienced with uppers, because they 
cover the broad and hard surface of the roof of the mouth. But 
the lower plate is supported on the rim of the lower jaw, sur- 
rounded by the muscles under the tongue, which frequently 
move. Lower dentures are not as firmly anchored as the upper, 
and sometimes there is a tendency, when eating, for them to 
stick to the mass of food, and even to be pulled out of place, a 
rather disconcerting experience for the wearer. 

In Dr. Freedman's invention, small Alnico magnets are placed 
in the plates, alongside the upper and lower molars, as shown 
in the illustration. Identical poles, either north or south, are all 
lined up in the same direction, so the upper and lower magnets 
push on each other with a force of about five ounces when the 
jaws are closed. Since the force of closing the jaws is about 
twenty pounds, the wearer of magnetic teeth has no trouble in 
closing his mouth; but the effect is of invisible springs, con- 
stantly pushing down on the lower denture and holding it in 

Magnetic material of a different nature, yet of great impor- 
tance in industry, is the steel required for the cores of trans- 
formers. These are used in the many places in distribution and 
use of electrical energy where voltage must be changed either 
stepped up or down. Essentially a transformer consists of two 
coils of wire on an iron or steel core. Alternating current is 
applied to one coil, the primary, and a current will flow from 
the other, the secondary. If the number of wires in primary and 
secondary are the same, the final voltage will be the same as 
you put in, but if the turns of the secondary are only half as 
numerous, the output voltage will be half of the input. Con- 
versely, with twice as many turns, the secondary will give out 
twice the number of volts applied to the primary. Since alter- 


nating current can be transmitted much more efficiently at high 
voltages than at low, it is the practice, at the generating station, 
to step it up to many thousands for transmission and then, 
where it is used, to step it down again, often in several steps. 

A transformer is most efficient if the core is a ring or an open 
rectangle, so that the magnetic lines of force which are respon- 
sible for its action can flow in a closed circuit. It is also better 
if the core is laminated rather than made in a solid piece. The 
laminations prevent "eddy currents" from flowing around in 
small loops inside the coil and wasting power. 

The properties desired for metal in a transformer are just the 
opposite of those which make a magnet permanent. The trans- 
former core should respond instantly to rapid changes, many 
times a second, of the magnetizing forces. In the early days of 
the G-E Research Laboratory, a great advance came when the 
youthful director, Dr. Willis R. Whitney, and a group of his 
associates investigated magnetic steel. Combined with inde- 
pendent work in England, this led to the adoption of a silicon- 
alloy steel, and the losses in the core were cut in two. 

Until recently silicon steel was made in L-shaped plates, and 
these were interleaved with one L pointing to the right, the 
next upside down and pointing left, so that an open rectangle 
was formed, The L-shaped plates were cut from a wider strip 
of rolled steel. 

In rolling steel, the atoms line up, giving it a "grain" roughlv 
comparable to the grain of wood. It has been found that the 
magnetic flow in the core is easier with the grain than across it. 
However, in the older silicon steels, this difference was not 
great. In co-operation with the Allegheny Ludlum Steel Com- 
pany, the metallurgists found a means of making silicon steel 
which could be rolled into strips while cold, instead of having 
to be heated. In this the flow along the grain is much better, 
and the flow across the grain much poorer, than in the older 
metal. With it L-shaped plates were no longer effective; for if 
one arm of the L is with the grain, the other must be across it. 
To permit the use of this new silicon alloy, however, an in- 


genious arrangement, called the Spirakore transformer, was 
brought out. The core is made of a continuous strip of steel, 
wound in a spiral like a clock spring. In this way transformers 
are made which cost less than the old types, yet are smaller, 
lighter and more efficient 

XL Mining the Ocean 

Around the middle of the last century, the "Electrolytic 
Marine Salts Company" was organized for the purpose of ex- 
tracting gold from the sea. Plenty of gold, for the benefit of the 
promoters, resulted; but it came from the pockets of the in- 
vestors rather than from the ocean. Actually, in a thousand 
gallons of sea water, there is about one cent's worth of gold; 
and it can be removed, though it costs considerably more than 
a cent to do so under present conditions. 

However, sea water also contains many other elements, some 
of them metals, and at present two of them are being recovered 
as successful commercial ventures. We think of sea water as 
salty, and correctly, too, for sodium chloride, which is common 
salt, is the most abundant compound dissolved in it. In a ton of 
sea water, there are about fifty-six pounds of salt. Next in 
abundance comes magnesium chloride, of which there are 
about 6% pounds. Then come other materials in still smaller 

After the introduction of ethyl gasoline had produced a 
demand for bromine in the form of ethylene dibromide, a 
chemical needed for making ethyl fluid, the usual sources of 
bromine were insufficient to supply the demand. There is 
bromine in sea water, though not in very large proportions 
only about two ounces to a ton but at this rate a cubic mile of 
the ocean would provide enough bromine for a plant producing 
one hundred tons a month to be kept in operation for nearly two 
hundred years. According to the estimates of geographers, there 
are more than 300,000,000 cubic miles of ocean, so the supply is 
practically inexhaustible. 

The first experiments were performed in the laboratories of 
the Ethyl Gasoline Corporation in co-operation with the 



General Motors Laboratories, and by them the process of re- 
covering this small proportion of bromine was perfected. Then 
a "pilot plant" was erected at Ocean City, Maryland, to try it 
on a semi-commercial scale. This demonstrated that the water 
treated should be very free from silt, or suspended matter. 

Further tests on a still larger scale, as mentioned earlier, were 
conducted aboard the S.S. Ethyl, the lake-type cargo vessel of 
4200 tons that was fitted out as a floating chemical factory. 
This made it possible to try clean sea water from a number of 
places. The equipment handled 7000 gallons of water per 
minute; and the success of the operation showed that extracting 
bromine from sea water was entirely practicable. 

Before this, however, the Dow Chemical Company had like- 
wise considered the problem of extracting bromine from the 
sea, employing practically the same method that they used in 
their Michigan plant for recovering it from natural brines. 
Essentially this was to treat the brine, in which bromine was 
present as bromides, or combinations with various metals, with 
chlorine. Since the chlorine has a greater affinity for these 
metals, it steps in as a sort of chemical co-respondent; the bro- 
mine atoms are divorced and left to shift for themselves. The 
Dow process uses a powerful stream of air to blow the bromine 
out of the solution after it is free. Then it is combined with car- 
bonates, from which it can easily and conveniently be used. 
From the natural brines, which contain some 25 per cent of 
solids, about 95 per cent of the bromine present has been con- 
sistently extracted. 1 

After careful study, the site for the first plant was selected on 
the coast of North Carolina, near Wilmington. A ninety- 
acre tract was purchased between the Cape Fear River and 
the ocean. This is north of the mouth of the river. Since the 

1 The process used on the S.S. Ethyl had been rather more complicated and 
less efficient, and employed another and more expensive chemical, aniline, in 
its operation. Tribromoaniline, instead of ethylene dibromide, had been pro- 
duced for combining with the tetraethyl lead. However, it was decided to use 
the Dow process, and in July, 1933, the Ethyl-Dow Chemical Company was 
incorporated, owned jointly by the two parent groups. 


water of all streams entering the Atlantic Ocean flows south- 
ward, this site was a great advantage the treated water, from 
which the bromine had been removed, could be exhausted into 
the river. Then it would flow into the ocean where it could not 
dilute the incoming water. 

The first working drawing was completed on August 14, 1933, 
and less than five months later, on January 10, 1934, the pro- 
duction of ethylene dibromide commenced Each day, at first, 
30,000 gallons of water passed through, yielding 15,000 pounds 
of bromine, an efficiency of about 90 per cent. Since then the 
capacity of the plant has been doubled, and a second one has 
been established in Texas. 

Sea water is slightly alkaline, so, at the start of the process, 
sulfuric acid is added to it. Then chlorine gas is introduced and 
the mixture is sprayed down the inside of a tower. Here the air- 
pressure force blows the bromine out and carries it up and over 
into another tower, where a sodium-carbonate (soda ash) 
solution is sprayed into it, and a solution of mixed sodium bro- 
mide and sodium bromate accumulates at the bottom. With the 
use of more sulfuric acid and steam, bromine is extracted as a 
heavy brownish-red liquid. Since this has a highly corrosive 
effect and is therefore difficult to ship, it is first made into 
ethylene dibromide by combining it with ethylene gas made 
from alcohol. 

The success of these plants clearly demonstrated the prac- 
ticability of recovering bromine from the sea, and immediately 
those familiar with the process began to wonder whether some 
others of the elements in the ocean could not be secured in a 
comparable manner. The next step was brought about by World 
War II, and America's decision to become the arsenal of the 

Airplane production requires, in enormous quantities, the 
two light metals aluminum and magnesium. Between 1927 and 
1940 the Dow Chemical Company had been the only American 


producer of magnesium. In 1914, at the outbreak of World War 
I, they had been using magnesium chloride, imported from 
Germany, for making the magnesium-oxychloride cements that 
were then widely used. When the supply was cut off, the 
company began producing its own magnesium chloride from 
the natural brine that was already furnishing its calcium 
chloride. In 1915, however, there was no commercial demand 
for magnesium metal, except in very small amounts for photo- 
graphic flash powder. It sold then for $5.00 a pound. 

However, the Dow chemists began producing the metal in 
1918, and developed a whole series of alloys with magnesium as 
a base, known under the general name of "Dowmetal." The 
strength, lightness and resistance to corrosion of these alloys led 
to wide use, especially, as already noted, in airplane parts. To 
produce the enormous quantities needed for war material, 
every source had to be explored, including the ocean. About 3.8 
per cent of the salts dissolved in sea water is magnesium. This 
is about 0.14 per cent of the total ocean, a figure which seems 
rather low. However, it means that there are about 4,555,000 
tons of magnesium in a cubic mile of the sea, or enough in a 
single cubic mile to supply 400,000,000 pounds a year (the 
projected U. S. production) for twenty-two years! 

Early in 1940, anticipating increased war requirements, the 
Dow company began the construction of a plant on the Gulf 
Coast of Texas to mine magnesium from the sea a process 
requiring that about eight hundred tons of sea water, which is 
the raw material, be handled for every ton of magnesium se- 
cured. The location is at the mouth of a river where there is a 
deep horseshoe bend. Formerly this bend frequently obstructed 
the river's course and caused floods, so, in 1929, a new channel 
had been dug straight from a point above the bend to the Gulf, 
and the old river course was left as a deep-water channel. It 
was the tongue of land inside the old horseshoe bend that was 

Sea water is taken from the new channel and the exhaust 


water poured into the old river. Its mouth is south of the ship 
channel. Currents along the Gulf Coast, as along the Atlantic 
shore, tend southward, so the waste waters are carried away 
from the intake. In addition to the magnesium plant, the Ethyl- 
Dow Corporation's bromine plant was erected on the same 
peninsula, as well as a Dow plant for obtaining useful chemicals 
from the plentiful supply of natural gas. So the whole group of 
factories form a curious combination their raw material is 
water and gas! 

Water pumped from the ship channel at the rate of a quarter- 
million gallons per minute is strained through screens, then 
divided, some going to the bromine plant, the rest to the 
magnesium installation. Of course there is plenty of water 
otherwise the same water might be used in both. The sea water 
is mixed with a thick paste of lime (made from oyster shells) 
which reacts with the magnesium salts in the water to form 
magnesium hydroxide. This in turn is treated with hydrochloric 
acid to form magnesium chloride, which is then dried. After 
that it is melted in a furnace, and an electric current decom- 
poses it into magnesium and chlorine. The metal, being lighter 
than the molten chloride, floats to the top, so it is skimmed off 
and cast into pigs two feet long and four inches square. Because 
magnesium is so light, however, these pigs weigh only seven- 
teen pounds each. A piece of iron the same size would weigh 
ninety-seven pounds. The chlorine given off is not wasted, but 
is fed into a gas flame to make more hydrochloric acid, which 
is used over again. 

The success of this process, and of the bromine plants, has 
naturally led chemists to look longingly at the other elements 
present in the ocean in such enormous quantities. Dr. Frank 
Wigglesworth Clarke, of the U. S. Geological Survey, once 
estimated that the volume of the ocean is 302,000,000 cubic 
miles. With 3.5 per cent of solid matter dissolved in the water, 
this would mean 4,800,000 cubic miles of salt, or enough to 
cover the entire United States to a depth of more than a mile 


and a half. Even of elements present in extremely small pro- 
portion there are still gigantic amounts. 

The possibility of securing gold from the sea has always been 
a most intriguing one, as witness the success (for its promoters) 
of the Electrolytic Marine Salts Company. Soon after World 
War I the great German chemist Fritz Haber, whose process 
is used for recovering nitrogen from the atmosphere, thought 
that he could get gold from the sea cheaply enough to help his 
country's economy. Unfortunately he used a figure for the per- 
centage of gold which, though it came from apparently good 
authority, was much too high; and he could not make the 
process commercially successful. 

Estimates of the gold content in sea water vary greatly, 
depending in part on the locality where the water is secured. 
There is some evidence that the water from the deep sea con- 
tains more than from the surface, but on the average there is 
something like a few parts per billion. The metal has been 
extracted, but the cost, at best, is about five times that of the 
value of the gold recovered. 

In an attempt, by usual means, to electroplate gold out from 
sea water, it fails to form in a solid crystalline mass at the 
cathode, the negative electric terminal. Instead it precipitates 
to the bottom as a fine powder, in colloidal form. If an inex- 
pensive means could be found to convert the colloidal into 
crystalline gold, the problem might be solved. 

Dr. Colin G. Fink, of Columbia University, has worked on 
this subject, and has found a way of making the gold deposit as 
a solid. This is done by rotating the cathode at high speed. But 
the process requires more complicated equipment, more current 
and more expense, so it is still unfeasible commercially. How- 
ever, Dr. Fink's studies have also revealed more about the way 
gold deposits out of solution. Even when the crystalline metal 
is formed, it goes through a colloidal step which previously had 


not been detected. So, as our knowledge increases, we may yet 
come to gold from sea water if indeed we want any more than 
we now have. But doubtless other important results will follow 
from these experiments, perhaps helping to obtain from the 
ocean metals of more real usefulness. 

XII. The Magic of Glass 

It is a curious fact that one of the very oldest of man-made 
materials should today be perhaps the chief characteristic of 
"modern" architecture. In many of these "functional" buildings 
the extensive use of glass is a most distinctive feature. Whole 
walls are made of glass bricks, doors are made of heavy sheets 
of glass without any metal edging, windows cover large open- 
ings and are often curved to conform to the line of the structure, 
while in the interior furnishings tables may be made of glass. If 
the building is modern, it is probably air conditioned; walls 
must be insulated against heat, and perhaps glass fiber performs 
this job, while the same fiber may even be woven into curtains 
and decorate the various rooms. 

Yet the history of glass goes back so far that no one knows 
who discovered it. Perhaps, as Pliny relates, it all began some 
five thousand years ago when pieces of limestone and natural 
soda were accidentally used around a campfire on an open 
beach, and the chemicals reacted with the sand to produce 
glass. Or more likely it started, perhaps by an analogous proc- 
ess, in some Neolithic cave as long as ten thousand years ago. 
Indeed, glass was used even before that, for there are natural 
glasses, of which obsidian is the best known. Primitive men used 
this for arrowheads and knives, as well as for decoration. They 
did not use it for most of the tasks in which we employ glass, 
however, because obsidian is black, and not transparent. 

Glass bottles for perfumes and other purposes were made in 
ancient Egypt, and some are preserved in our museums. In 
Rome too fine glass was made, and, at about the beginning of 
the Christian era, the secret was found of making glass trans- 
parent and clear. This art the Italian workers brought to its 



height in Venice during the sixteenth century. Incidentally, 
there is a word often used in our language which goes back to 
the Italian glass makers. It is the word "fiasco." In those days, 
the making of glass was largely a process of trial and error, for 
the scientific controls of the twentieth century were still long 
in the future. But when an Italian glass blower got some glass 
that was not good for other purposes, he could still make it into 
a flask a "fiasco" for wine. And so now when something we 
plan turns out badly, we also say that it is a fiasco. 

Soon after the first English colonists arrived in Jamestown, 
the first glass factory was established in America. This was in 
1609; and in the first cargo exported to the homeland, some of 
the colonial glass was included. Mostly the Virginians made 
bottles, beads and trinkets to barter with the Indians. This 
factory lasted only a few years, and a second, established in 
1621, was similarly short-lived. By the time of the Revolution, 
however, many glass factories were in operation, and in still 
more recent years a number of the fundamental advances in 
glass technique have come from American researches. 

With many of the products that are described in this book, 
such as rubber, gasoline and explosives, it is possible to tell the 
chemical formula; but this cannot be done with glass. Actually 
glass is a liquid, though a rigid one, and has no regular atomic 
pattern, repeated over and over again. The best we can do is to 
say that a typical composition of glass contains 100 parts of 
sodium oxide, 67 parts of calcium oxide and 452 parts of silicon 
dioxide. However, physicists have determined something about 
the generalized arrangement of the atoms. It seems that each 
silicon atom is at the center of a tetrahedron (a triangular 
pyramid, having four faces and four corners) with an oxygen 
atom at each corner. Then each of these oxygens in turn has a 
second silicon atom, which is the center of another tetrahedron, 
attached to it. That is, the oxygen really forms a corner of two 
tetrahedra, which may be nicely arranged in exactly opposite 
directions, or else may be twisted around so they almost touch. 
This is very different from the neatly arranged latticework of 


atoms in a crystal, such as natural quartz. Glass is definitely a 
non-crystalline substance. 

Edison's invention of the electric light in 1879, and its rapid 
development in following years, provided a great stimulus for 
automatic glass machinery, and a departure from the time- 
honored methods of making by hand such things as bottles. In 
the hand process, a long blowpipe was dipped into a pot of 
molten glass, the drop that adhered was inserted into the top of 
a mold, and the glass blower blew. Mighty lungs were a 
requisite for such a profession. The soft glass filled up the mold, 
it was opened, and the bottle was the result. The first machines 
followed more or less this general technique, but in 1899 ap- 
peared the first conception of the Corning fully automatic 
machine for thin-glass objects, such as electric-light bulbs, thin 
tumblers and Christmas-tree ornaments. This, which was a 
complete departure from the old practice, permitted great 
speed in operation and enabled the glass manufacturers to keep 
up with the demand that was growing so rapidly for this new 
source of light a speed which the bottle machines could not 

From the furnace into the automatic machine comes a one- 
inch stream of melted glass which passes between rollers that 
flatten it into a ribbon. In one of these rollers is a depression, 
and every time the ribbon comes against this a lump, or 
"biscuit/' is formed. The ribbon passes to a moving belt with 
regular openings an inch or more in diameter; and it is timed so 
that each biscuit comes over one of the holes. Still soft, the glass 
in the biscuit sags through the hole, making a pear-shaped drop 
roughly the size and shape of the finished bulb. The drops grow 
longer. Then molds, lined with wet charcoal, close about them. 
To prevent marks from showing, the molds rotate around the 
glass drop, the water on the charcoal being turned into steam 


by the heat so that there is actually a cushion of steam between 
glass and mold. Next, the nozzle of an air pump is applied from 
above to each embryo bulb, and air is blown in to make it fill 
out to the proper shape. At the end of the line the molds open, 
the bulbs are knocked off and pass to ovens where the tempera- 
ture is gradually lowered. That is, the bulbs are annealed. 

The speed of such machines is unbelievable. Perhaps it took 
you a minute to read the foregoing two paragraphs. In that 
time, one of these machines would turn out from 400 to 600 
bulbs; and they have been operated as fast as 700 per minute. 
One might wonder what happens to the rest of the glass ribbon, 
the connecting portions that were not formed into biscuits. 
They are not wasted; they just go back to the furnace as scrap, 
to be melted over again. Bulbs that may be defective, or which 
are accidentally broken, can be salvaged in the same way, for 
these processes use more than 50 per cent of "cullet," as the 
scrap glass is termed. It is largely through such efficiency of 
production that a 60-watt Mazda lamp, for instance, which cost 
originally $1.75, and 40 cents in 1915, can now be purchased for 
less than 15 cents. Once the automatic bulb machine was 
thought to have thrown men out of employment. Instead, by 
making lamps and radio tubes so cheap and plentiful, it has 
made many new jobs. 

Glass is not a single material, like, let us say, iron, or alu- 
minum. Rather it is a class, for glasses differ just as do metals. 
Some glasses are as dense as cast iron, while others are lighter 
than aluminum. Other important properties vary just as widely, 
and the compositions are very different. 

Generally the job of glass is to transmit light; but by varying 
the composition the particular wavelengths, or colors, that it 
lets through can be selected as desired. It can be made to trans- 
mit ultraviolet rays, which are invisible. It can be made to cut 
off the shorter, harmful, ultraviolet rays, yet transmit the longer 


ones that are beneficial. Bulbs for X-ray tubes can be made out 
of two kinds of glass. One lets these still shorter wavelength 
radiations through in the desired direction, while the other, 
constituting the remainder of the tube, stops them and protects 
the operator. And for skylights and windows there are glasses 
that cut out infra-red or heat rays, yet allow visible light to 
pass freely. 

Though we think of glass as something that is easily broken, 
some varieties have strength comparable with steel, and others 
can be hammered, or bent, or exposed to heat and cold without 
damage. Much of this is owing to the work of the Corning Glass 
Works, which produced the first of its famous Pyrex glass in 
1915. This was accomplished when it was found how to make a 
glass which varies only slightly with changes in temperature; 
that is, which has a low "coefficient of expansion/' For Pyrex 
glass this is about a third of the coefficient for ordinary window 
or bottle glass, and that makes the difference. Glass is a poor 
conductor of heat. Consequently, if you have a thick piece, and 
heat is applied to the surface, the outside will expand, yet poor 
conduction will prevent the interior from heating as quickly, so 
the inside will not expand as much. If the change in size of the 
outer part is too great, the glass will crack. In the Pyrex glasses, 
the expansion is too little to cause such cracking. 

Quartz, which is pure silicon dioxide, has a very low co- 
efficient of expansion, and has been used for scientific and 
chemical apparatus, such as tubing, breakers and flasks. It also 
has strong resistance to chemical attack. However, it is ex- 
pensive, and since its properties are approached by the proper- 
ties of Pyrex, that glass now finds extensive uses in industry and 
laboratory, as well as for casseroles and pie plates in the home. 

A further improvement, which brought glass even closer to 
quartz, came in 1939 when the Corning Glass Works introduced 
"shrunk" glass, under the name of Pyrex "Flameware." The 
older Pyrex cannot be exposed to an open flame without crack- 
ing, but this can be. Almost unbelievable demonstrations are 


made of its resistance to temperature differences. It can be 
heated to redness, then plunged into ice water without crack- 
ing, or a dish of the material may be placed on a piece of ice 
and molten iron poured into it, again without damage. 

This was a result of fundamental research into the properties 
of glass, made at first without any particular commercial ap- 
plication in mind, other than the knowledge that the more 
that was known, the more likely it would be that useful new 
developments might be made. In order to make glass strong, 
it is the usual practice to anneal it; to cool it slowly, especially 
over certain critical temperatures. Then no strains are set up, 
such as might result if the outer part cooled more quickly than 
the inner. However, it was found that prolonged heat treat- 
ment, at the temperatures used in annealing, made some glasses 
very much less resistant to attack by chemical reagents and even 
by water. 

A further study of this effect over a number of years showed 
that, with certain chemical compositions, the glass actually 
separates into two parts, or phases. One is almost entirely pure 
silica, which is the common name for the silicon dioxide that 
makes up most of quartz. The other phase contains boric oxide, 
alkali and other constituents. Since the latter is easily dissolved 
by acids it is possible to place the heat-treated glass in an acid 
bath, thus extracting the second part, about a third of the whole. 
Then the mass becomes a sponge of silica, with microscopic 
pores remaining where the acid has done its work. The silica is 
unaffected by acid. Full of holes, the object at this stage has a 
cloudy appearance. It can then be heated once more, and if 
this is properly done, the pores close, the entire object shrinks 
about 35 per cent, yet retains its original shape with remark- 
able fidelity. A pie plate, originally 10% inches in diameter, will 
thus shrink to about nine inches. Then it is practically pure 
quartz, and can be used on an open flame without cracking. 
These same advantages have made the material of importance 
to the chemist as well as the cook. 


In direct contrast to annealed glass is the tempered glass 
used for doors, and other purposes where great strength in re- 
sisting blows, rather than extreme temperatures difference, is 
wanted. The process of making this is analogous to the case 
hardening of metals. First the glass is formed to the proper 
shape, then it is reheated to a temperature well above the an- 
nealing point. At this temperature it is suddenly exposed to 
jets of cold air, or it is immersed in oil, or in various molten 
salts. This forms around the article a skin of glass which is try- 
ing to expand, and which is therefore under constant com- 
pression, pulling against the tension of the interior of the mass. 
Though constant strains are set up, these are balanced by the 
tendency of the glass to hold itself together; and thus the 
strength of the glass is increased many times. Pieces of tem- 
pered glass can be hit with a hammer or bent considerably 
without breaking them. 

A blow of sufficient violence, of course, will puncture the 
surface layer and even break tempered glass. Then its behavior 
is different from that of ordinary glass, for as the stresses are 
suddenly released, the article shatters into countless tiny pieces. 
Fortunately, these fragments are more or less rounded, and are 
not as dangerous as the sharp splinters of ordinary glass. 

To make glass that will not shatter, safety glass has been 
developed. In one form, a wire netting is laid into the glass 
while soft, and this holds the pieces together even if the sheet 
breaks. But as it is desirable to maintain clarity, laminated 
safety glass is more common. The first laminated glass was made 
for decorative rather than safety purposes when an Englishman 
named Fullicks, in 1885, obtained a patent for cementing pieces 
of variously colored glass between two sheets of clear glass. 

Laminated safety glass was invented by another English- 
man, John Wood. In 1905 he was granted a British patent for 
a method of cementing a sheet of Celluloid between two sheets 
of glass, using Canada balsam as the cement. The plastic, 


Celluloid, was transparent, yet it held the pieces of glass to- 
gether if the sheet broke. Production started, but lack of de- 
mand made the venture a failure financially. In 1910 a process 
was patented using gelatin instead of Canada balsam as the ad- 
hesive, and the resulting material was produced in England as 
"Triplex" glass. During the First World War it was extensively 
employed for gas-mask lenses, airplane windshields and visors, 
and automobile windshields. FoUowing the war, as closed auto- 
mobiles became more and more popular, the demand increased, 
and finally the use of safety glass for automobiles was made 
mandatory in most of the United States. 

Celluloid, or cellulose nitrate, has disadvantages, some of 
which have been mentioned earlier. For one thing, the ultra- 
violet radiation of sunlight makes Celluloid decompose; it be- 
comes brown and separates from the glass, which then is no 
longer non-shatter able. Cellulose acetate has been used in- 
stead, and is better, since it is not as much affected by sunlight. 

Modern high-test safety glass makes use of one of the newer 
synthetic resins; a vinyl acetal plastic, which has considerable 
flexibility, combined with transparency and great strength. It 
sticks firmly to glass without the use of an adhesive, and is un- 
affected by ultraviolet light or by considerable temperature 
changes. 1 Generally, the vinyl acetal resin is used between 
sheets of glass that are quite thin, not more than one-eighth of 
an inch and this is done paradoxically, to make it easy to 
break. For then most of the energy of an object that hits it is 
taken up by the plastic rather than the glass. At a meeting 
held at the Franklin Institute, where this glass was introduced, 
Dr. Edward R. Weidlein, director of the Mellon Institute of 
Industrial Research, described its advantages in this way: 2 

We are all familiar with the fact that a baseball catcher pulls his 
hand back with the ball when he is catching a "fast one." This practice 

1 Glass made with this as an interlayer has come as the result of an effort 
by the Carbide and Carbon Chemicals Corporation, E. I. du Pont de Nemours 
and Company, the Libbey-Owens-Ford Glass Company, the Pittsburgh Plate 
Glass Company and the Monsanto Chemical Company. 

2 Industrial and Engineering Chemistry. May, 1939: p. 563. 


is to decelerate the baseball over a certain displacement so that all 
its kinetic energy is absorbed over a greater period of time, with the 
result that there is less sting in the ball. The same phenomenon makes 
it less painful to land in a firemen's net than on a concrete sidewalk. 

Similar conditions hold for safety glass. If the kinetic energy of a 
fast-flying object that strikes a piece of laminated glass can be dis- 
tributed over a greater displacement, there is much less chance that 
the plastic interlayer will fail; moreover less damage is done to the 
object that hits the glass. This latter consideration is important if the 
object happens to be the driver or passenger in a car. 

Theoretically, then, from the standpoint of safety alone, the ideal 
material for the construction of windshields and sidelights in vehicles 
would be a very elastic substance that would act more like a firemen's 
net than a piece of boiler plate in case of accident. Because such an 
elastic material has not been found that would be acceptable for use 
by itself, advantage had to be taken of the clarity and hardness of 
glass to prevent the plastic becoming useless by abrasion. Laminated 
glass can be rendered safer by decreasing the thickness of the glass 
and so decreasing the amount of energy necessary to break it before 
the flexibility of the plastic comes into play. 

Among the latest wonders of glass research is one that you 
would hardly recognize as a member of this family. It is black, 
non-transparent, lighter than cork and it can be sawed or drilled 
with ordinary wood-working tools. "Foamglas" is its name, and 
it has been developed after several years of research by the 
laboratories of the Pittsburgh Corning Corporation, which is 
owned jointly by the Pittsburgh Plate Glass Corporation and 
the Corning Glass Works. 

Chief use of Foamglas, which floats in water, is to replace 
such things as cork, balsa wood, cellular rubber and kapok as 
a filling for life preservers and life rafts. Not only did it help 
to relieve a shortage of these imported materials; it also is su- 
perior to them, since it is odorless, fireproof and vermin proof. 
It is even more buoyant than cork, which weighs 14 to 16 
pounds per cubic foot, as a cubic fot of Foamglas weighs only 
ten pounds. This is about the same as average grades of balsa. 


In contrast, ordinary glass weighs 150 to 175 pounds per cubic 

Similar to the way in which yeast or baking powder raises 
bread by the formation of small cells containing carbon dioxide 
is the way that this light-weight glass is made. A little pure car- 
bon is mixed with ordinary glass. When heated to the proper 
temperature, gas is formed, and the glass is puffed up, so that 
its density is about a fifteenth of what it was originally. Very 
exact control of time and temperature is needed in the process 
to secure rigid slabs in which the gas-containing cells are uni- 
formly small and sealed off from each other. 

Not only does Foamglas replace cork as a buoyant element; 
it also is taking its place as an insulator against heat, in the cold 
rooms of dairies, meat-packing plants and breweries. Even solid 
glass is a poor conductor of heat, and in combination with the 
gas cells it forms a most effective insulator. 

Probably the glass product that has the least resemblance to 
the familiar concept of glass as a hard transparent substance, 
however, is Fiberglas, which is used both in the form of soft 
wooly fibers for insulation of heat and sound, and as a beau- 
tiful silklike fabric, available in practically any color. 3 Heat in- 
sulation on ships of the U. S. Navy in 1932 was one of the very 
first applications of Fiberglas, for it met the requirements of 
naval architects who had asked for a fireproof insulation "that 
would be light in weight and take little room so that it won't 
encroach upon valuable cargo space and add to the deadweight 
of the vessel. It must withstand salt water and salt atmospheres. 
It should not rot, or decompose or feed vermin. It should not 
absorb cargo odors and it can't cost more than present ma- 

Merchant ships soon used it, too. Then it was applied in 

3 This was largely the result of work by Games Slayter, now director of 
research of the Owens-Corning Fiberglass Corporation, with the aid, among 
others, of John H. Thomas. In 1931 they succeeded in devising a practicable 
method by which glass can be drawn into fibers. Pilot plant operation demon- 
strated that this could be done on a large scale, and the company was organized 
in 1938 as a joint offspring of Owens-Illinois and Corning, both firms having 
shared in the development. 


dwellings and other buildings, keeping heat outside during the 
summer, and inside in the winter. Fiberglas is also coated with 
an adhesive that catches dust. Then, boxed in cardboard frames 
behind grills, it forms an effective filter for heating, ventilating 
and air-conditioning systems. 

It was in 1936 that fibers strong and pliable enough to be 
woven into cloth were produced, and this opened a whole new 
field for the material. The great advantages of such a fabric are 
that it will not shrink, stretch, rot or burn, is not harmed by 
moisture, and will not fade. This makes it advantageous for use 
as draperies, bedspreads and table cloths. Neckties too have 
been made from it. In tapes and braids, it was found to be an 
excellent electrical insulating material. 

An interesting use for Fiberglas is as insulation in electrically 
heated diving suits provided in the U. S. Navy for deep-sea 
divers. Formerly divers were supplied with compressed air, the 
usual mixture of oxygen and nitrogen, when they were below 
the surface. Physiological experiments, however, proved that a 
mixture of oxygen and helium has many advantages, particu- 
larly in preventing attacks of the dreaded "bends." However, 
this mixture tends to make the divers very cold. As this reduces 
their efficiency, it is then necessary to provide them with diving 
suits which are electrically heated. For insulation, Fiberglas 
was found to be the only material that was completely safe. 

In preparing Fiberglas, the original glass is molded into mar- 
bles, each weighing about a quarter of an ounce. Any with im- 
perfections can be discarded, and those that survive the in- 
spection are remelted. The furnace chamber has in its base 
many fine holes, corresponding to the spinnerets described in 
connection with synthetic fabrics. The filaments of glass that 
flow through these holes perhaps 200 or more are gathered 
into a strand by a high-speed winder. Instead of continuous 
thread fibers, they can be made in staple-lengths, running be- 
tween eight and 15 inches, more than the lengths of the fibers 
in the best long-staple cotton. Either kind of glass fiber can be 
spun and woven on standard textile machinery. Fabrics from 


continuous filaments are smoother and harder finished, but 
those from the staple-length fibers have greater bulk, which 
sometimes is desirable. The fibers are tremendously strong; 
in fact, their tensile strength is greater than that of steel. 

To make heat insulation, the marble stage is not necessary, 
and the glass ingredients can be melted in larger furnaces. Just 
as in making the staple fibers, the threads of melted glass flow- 
ing through the tiny holes are caught by jets of steam. The 
resulting fibers gather on a moving belt, which takes them all, 
as an endless blanket, to the place where they are fabricated. 


But, of all the parts which glass has played, the one in which 
it has had the widest influence is as optical glass. It has enabled 
the astronomer to see and photograph galaxies so distant that 
their light, traveling at a speed of about 11,000,000 miles a min- 
ute, takes 500,000,000 years to reach us. With the spectroscope, 
using glass lenses and prisms, attached to his telescope, he has 
analyzed the stars, studied matter under conditions of tempera- 
ture and pressure that we can never hope to imitate on earth. 
From these studies he has learned facts that help him to under- 
stand the behavior of atoms even of terrestrial matter. 

In laboratories that deal with more mundane subjects, too, 
the scientist acquires his knowledge by means of glass. He also 
uses the spectroscope to look into matter. Through the lenses of 
the microscope, he sees the minute structure of metals. When 
he wants to distinguish friend from foe, he studies germs and 
other organisms, some of which cause disease, while others are 
beneficial. He uses photographic lenses to form images which 
make records far more accurate than any drawing. 

Two things can happen to a light beam as it passes from the 
air into glass and then out again, or from one kind of glass to 
another. The final path of the beam may be in a different direc- 
tion from the one which it followed originally. This is called 
"refraction/' and the ability of a glass to refract is measured by 


its refractive index. But also a beam of white light may emerge 
as a spectrum, a rainbowlike range of colors. This happens be- 
cause different colors or wavelengths, which make up white 
light, are refracted to a different degree. Long waves of red 
light are bent least, while the waves of violet, about four- 
sevenths as long, are bent most. Consequently, the colors are 
sorted out into a spectrum: red, orange, yellow green, blue 
and violet. This is called dispersion. 

Because of this fact it is not possible to make a single lens, 
of only one kind of glass, which will give a perfectly clear 
image in white light. If it is focused to make the image of the 
blue rays sharp, the reds will be blurred. If the reds are fo- 
cused, there is a halo of blue around them. 

Sir Isaac Newton, who first studied the effect of a prism in 
making a spectrum, came to the conclusion that all kinds of 
glass varied in refractive index and powers of dispersion to the 
same extent that is, any two glasses which differed in one 
would differ in the other quality too. But later, in 1729, an 
English barrister named Chester Moor Hall showed that New- 
ton had been mistaken. By combining two lenses, one convex, 
the other concave, he produced an achromatic lens, one which 
focused all the colors at the same distance. The first, the convex, 
lens formed an image which would have the colors blurred. But 
as the light rays passed through the second, the concave, lens, 
the dispersion of that one acted in the opposite direction and 
brought the colors into line again, compensating for the effect 
of the convex element. The second lens introduced refraction 
in the opposite direction too, and tended to restore the light 
rays to their original line; but for the same amount of dispersion 
its refractive index was less, and it did not completely undo 
the work of the first lens in bending the rays and forming the 
image. The result was an image which was achromatic, or free 
from unwanted color. In 1758 an optician named John Dollond 
introduced the achromatic lens commercially, and he is often 
given credit, though wrongly, for its invention. 

Different types of glass were available to these early opticians, 


but the manufacture of modern optical glass, on a scientific 
basis, began in 1862 in Germany when Ernst Abbe, profes- 
sor of physics at the University of Jena, began his collabora- 
tion with the Schott glass works in the same Thuringian town. 
Abbe also took over the small business of a microscope maker 
named Carl Zeiss, and, with the aid of the new type of glass, 
made this into one of the most noted names in optical manu- 

Before Abbe's time only five or six elements were in general 
use, and from them were made two principal types of optical 
glass. One was called "crown," with lime; the other, termed 
"flint," contained lead oxide. But Abbe and Schott added about 
twenty-five new elements to those used. This gave them an 
enormous range of optical properties, which could be obtained 
as desired; and optical systems could be made which were 
free from many of the faults that were inherent in the earlier 

A few years ago an American chemist, Dr. George W. Morey, 
of the Geophysical Laboratory of the Carnegie Institution of 
Washington, was granted patents on a series of glasses using 
still more elements, and someday these may prove as great a 
step forward as did Abbe's work. Dr. Morey makes use of rare 
chemical elements such as yttrium, lanthanum, columbium and 
hafnium, many of which are members of the "rare earth" group 
of elements. The great advantage of these glasses is that they 
have still higher refractive indices, yet with no more dispersion. 
Previously, the highest index that had been attained was about 
1.75, while Dr. Morey has gone above 2.00. Only the diamond, 
with 2.41, has a higher index. The rights on this invention, 
which will give the lens designer an increased range of ma- 
terials to work with, have been assigned to the Eastman Kodak 

Optical glass has assumed even greater importance with the 
entry of the United States into World War II. Fortunately, the 
work of World War I created an American industry which is 
able to supply our needs, and, as exemplified by Dr. Morey 's 


work, to give us new materials as well. Up to 1914 all our op- 
tical glass had been imported, mostly from Germany; and by 
1917 the supply of glass which our manufacturers had on hand 
had been practically exhausted making equipment for the Al- 
lies. This meant that, when we joined them in 1917 and the 
demand increased still further, the supply ran out entirely. 
Citizens were asked, as in World War II, to lend their binoculars 
to the Navy, and to let the Air Corps have their large photo- 
graphic lenses. 

Even to make the pots in which glass was prepared, German 
clay was required because it was free from iron. Such a minute 
quantity of iron as a few tenths of one per cent will contaminate 
glass, reducing its transparency. Nine different kinds of glass, 
it was estimated, were needed to produce instruments which 
the government required, but only two had previously been 
made in the United States. According to Dr. Arthur L. Day, 
former director of the Geophysical Laboratory, who had a 
leading part in establishing an American industry, the making 
of optical glass had been largely a secret process. "At the time 
of the war," he wrote later, "almost no authentic information 
had ever been printed. In France, it was a Government monop- 
oly; in England, practically so. In Germany, the industry was 
virtually concentrated in a single firm whose secrets were its 
own. Optical glass formulas were never allowed to become 
known even within the plant where it was made." 

But dark though the picture looked, two groups were or- 
ganized to study the problem. One, from the Geophysical Lab- 
oratory, worked with the Bausch and Lomb Optical Company 
in Rochester; the other, from the National Bureau of Standards, 
worked with the Pittsburgh Plate Glass Company. At the end 
of four months the Bausch and Lomb unit had started pro- 
duction, and by the end of 1917 its output was 40,000 pounds 
per month. 4 After 1918 the work was continued, mostly by 

4 Later the Spencer Lens Company, of Buffalo, which is now a division of the 
American Optical Company, was asked to tackle the problem. A glass-making 
plant was erected at Hamburg, N.Y., under Dr. Morey's direction. 


Bausch and Lomb and the National Bureau of Standards, and 
substantial quantities of glass, of numerous grades, were manu- 
factured for government requirements. So now we have both 
the knowledge, and the plants, to make glass for the many opti- 
cal instruments needed for war. 

Only in recent conflicts have these been important. Back in 
the Civil War, for example, cannon could not fire much farther 
than the gunner could see, and accurate instruments were not 
required. When the range of guns was increased to as much as 
fifteen miles, it became possible to fire beyond the horizon; 
and at this distance a slight error in aiming, which might only 
put the projectile a few feet away from its mark at a mile, would 
make it miss by many yards. 

On the gun itself there now must be an accurate panoramic 
sight, which is an optical instrument. Lenses of aerial cameras 
take photographs to guide the gunners. Enemy aviators are 
trying to do the same thing, so there are anti-aircraft guns. The 
rapid movements of the planes make them difficult for the gun- 
ners to follow, but complicated pieces of mechanism, combined 
range finders and calculating machines, automatically compute 
the data for aiming the guns. Sometimes, by means of ingenious 
electrical controls, these are connected with the directing mecha- 
nism and automatically aimed. 

In the airplanes, not only are there camera lenses but also 
optical bomb sights. To enable the pilot to tell where he is, 
from measures of the height of the sun and other celestial 
bodies, he has a special aircraft sextant, designed for rapid read- 
ing. On the sea there is the sextant used by the navigator, who 
has a little, though not very much, more time for his work 
than the aviator. There are the binoculars with which the officer 
on the bridge watches for submarines. A range finder on the 
ship tells the distance of an enemy, and on the guns, too, are 
optical sights. The periscope with which the commander of 
the submarine sights his prey, then aims his torpedo, is a most 
intricate example of optical science. 


In an optical system such as a periscope, where there are 
many separate pieces of glass, a great deal of light is lost by 
reflection. When a light beam hits a glass surface, most of it 
goes through, but a small percentage is reflected. That is why, 
if it is very bright and you are outside, you may have difficulty 
seeing in a window. If there are ten glass elements ( and many 
optical systems have even more), the few per cent lost at each 
one will amount to a considerable total and the brightness of the 
final image will be materially reduced perhaps to a quarter 
of the original brilliance. 

As early as 1892 H. D. Taylor, in England, found that lenses 
on which a film of tarnish had formed were not deteriorated but 
were actually improved, since the glass surfaces did not reflect 
so much light. And if the light is not reflected, it is added to 
that which passes through. Several scientists in the past decade 
have devised methods of giving glass such a film artificially. 
These have to be a certain thickness just a quarter the wave- 
length of light because light waves have to enter a polished 
surface slightly before they can turn around to be reflected, and 
in this space they do not have room to do so. Dr. Katharine 
Blodgett, of the General Electric Research Laboratory, was one 
of the first to make these films, another was Dr. John Strong, 
at the California Institute of Technology, and a third was Dr. 
C. Hawley Cartwright, at the Massachusetts Institute of Tech- 
nology. Unlike the films used by Dr. Blodgett, which easily 
rubbed off the glass, Dr. Cartwright's films, made of the fluo- 
rides of lithium, magnesium, calcium and sodium, are more 
permanent; and a company was organized to apply these com- 

Essentially the same method was adapted to large-scale work 
by Dr. C. W. Hewlett and C. N. Moore in the General Electric 
Research Laboratory; and it is now being used to treat the glass 
covers of many instruments, such as ammeters and voltmeters. 
This makes them much easier to read when they are mounted 


on a switchboard, for there is no danger of the meters' indica- 
tions becoming temporarily invisible because of chance surface 
reflections. Dr. Hewlett's method is to place the glasses in a 
clip, held by a magnet to the interior of a large iron sphere from 
which the air is exhausted. A tray of magnesium fluoride inside 
is heated, and when the salt evaporates it deposits on the cold 
glass surfaces. The time is adjusted to give the proper thickness. 
At first, the tray was placed at the center of the sphere, but it 
was found that uniform films were obtained only if the tray it- 
self were on the surface of the same sphere as that formed 
by the glasses. 

Dr. Blodgett showed also that chemical treatment of glass 
could produce a non-reflecting film. She used glass containing 
lead, some of which was leached out with nitric acid; a process 
somewhat comparable to that involved in the first stage of mak- 
ing shrunken glass. The film here seems to be practically pure 
quartz; at least it was found to have the same refractive index 
as quartz. Two scientists, Drs. Frank L. Jones and Howard J. 
Homer, working at the Mellon Institute under a Bausch and 
Lomb Optical Company Fellowship, studied similar methods 
and showed how the film could be baked after its application 
with considerable increase in its durability. 

Toward the end of 1941, the Radio Corporation of America 
announced a method which had been developed in their labora- 
tories by Dr. F. H. Nicoll, of exposing the glass briefly by hydro- 
fluoric acid vapor. This etches the surface and leaves behind a 
thin film of calcium fluoride. This film, it is reported, is very 
tough; it can be washed with water and alcohol and heated to 
high temperatures without damage. Such glass will be useful 
in television receivers, where the pictures are painted with elec- 
trons on the face of a glass tube, over which is a glass protector 
plate, and then a mirror in which the picture on the tube is 
seen. Applying the film to these glass surfaces will cut down 
the loss of light, just as it will in a system of lenses. 

Despite such advances as these with so old a material as 
glass, there is still room for much further progress. According 


to Dr. Eugene C. Sullivan, director of research of the Corning 
Glass Works, where so many of the past developments have 
been made: "In the developments still hatching in the labora- 
tories there is nothing to indicate an end in the unfolding of 
the mysteries of glass. The glassmaker still dreams of the value 
to mankind of an easily melted glass which could be machined 
in a lathe, which bent instead of breaking, and which in or- 
dinary use had the strength of steel." 
Perhaps that, too, will eventually come. 

XIII. Higher, Faster, Farther . . . 

From the ill-fated attempt of Icarus to the experiments about 
the beginning of the twentieth century by so distinguished a 
scientist as Samuel P. Langley, man dreamed of flying. Then, 
in December, 1903, the Wright brothers made their flight over 
the sandy beach of Kitty Hawk, pulled by a twelve-horsepower 
motor. In a second less than a minute they covered 850 feet 
and attained a speed of about thirty miles per hour. From that 
beginning, in less than four decades, have come the long-range 
planes of today, able to carry heavy loads for thousands of 
miles, and the high-speed craft, reaching velocities of around 
500 miles per hour. And if it be objected that unscrupulous men 
have prostituted these gifts, then think of the benefits that, in 
proper hands, they can confer on mankind in the future. 

Research made possible the first flights and has been respon- 
sible for the advances since advances which, impelled by war 
needs, have continued at a greater rate than ever. The Wright 
brothers performed research, with the use of gliders and mod- 
els, in a crude sort of wind tunnel. Through such experiments 
they learned the secret of securing longitudinal balance, by 
warping the trailing edges of the wings in opposite directions. 
Such a control had been lacking in the models previously con- 
structed, a factor at least partly responsible for their failure. 

It was quite fitting that the "Jennies" and other biplanes of 
the days of World War I were called "crates." Bleriot and other 
early designers, to be sure, had tried monoplanes, but it was 
difficult to give them adequate strength. After all, as a famous 
British aeronautical engineer, Dr. H. E. Wimperis, has pointed 
out, the biplane was simply an adaptation of the familiar girder 
construction with an upper and a lower boom. This was the 
manner in which engineers had been used to taking care of 



structures which tended to buckle. It is small wonder that they 
applied the same ideas to aircraft. 

That this type of construction, with the engine in between 
the wings, caused great air resistance, was relatively unimpor- 
tant because of the low speeds of that era. But as speeds were 
increased by brute force by simply raising the power of the 
engine streamlining became essential. The single wing of the 
modern plane has an upper and a lower surface, so it differs 
materially from Bleriot's monoplane; and these surfaces are con- 
nected by a girder structure. Actually what has happened, 
though, is that the upper and lower wings of the biplane have 
came closer together, and are joined at front and back by the 
closing in of the space between these surfaces, so that air is 
not disturbed by passing around the connecting members. 

Since 1918, aeronautical designers have "cleaned up" the 
outline of their planes. Not only have unnecessary excrescences 
been eliminated; the ones that were once thought necessary are 
also gone from the plane in flight. For instance, a plane certainly 
must have a landing gear it will not be of much use if it can- 
not come to earth and stop. But to get rid of it in flight modern 
designers have made it retractable. The wheels fold up into 
the wings, and are covered by a smooth door. It was also found 
that the rounded heads of rivets which hold the metal skin of 
the plane to the framework produced a noticeable drag so they 
are now countersunk, leaving the surface entirely smooth. 

In the Hall of Aviation in Philadelphia's Franklin Institute 
is an instructive exhibit which gives a good idea of why an air- 
plane goes up. It shows a model wing, held in an air stream. 
In a row, around the top and bottom of the wing from front to 
back, is a series of small holes, each connected by a tube to a 
pressure gauge. Thus it is possible to see immediately the way 
the pressure or lack of it is distributed. As might be expected 
there is positive pressure below the wing, but there is negative 
pressure suction on the upper surface. The principle that 
causes this was discovered many years ago by the physicist 
Daniel Bernoulli: the faster air moves over a surface, the less 


is the pressure that it exerts on that surface. So the aeronautical 
engineer gives the cross section of the wing such a shape that 
the air moving across the top has farther to go and hence 
must travel faster than that which moves along the bottom. 
Improvements have been made, but still further advances are 
in sight. It has been reported that engineers have now in the 
laboratory a new wing that will be twice as effective as the best 
of the older types. 


There are two types of aircraft, often confused in the public 
mind, which do not depend at all on wings for their lift, though 
the Bernouilli principle is still involved. One is the autogiro of 
the Spanish inventor, Juan de la Cierva. The faster a wing 
moves, the greater is its lift. Consequently, a plane intended for 
low speeds for private flying, for example usually has wide 
wings, while a high-speed pursuit plane has them narrower. 
What de la Cierva did, essentially, was to put four narrow 
wings on a rotor so they could spin around. Hence their speed 
through the air is much faster than that of the autogiro as a 

In the first models no power at all was applied to the rotor, 
and, in order to give the ship enough lifting power to take off, 
it was necessary for the pilot to taxi around the field, pulled 
forward by the propeller which performs the same function as 
in any other aircraft. Later, to allow takeoff in a confined space, 
the rotor was connected to the engine, which could start it 
spinning; but after the ship was in the air the rotor was thrown 
out of gear and allowed to spin freely. The advantage of this 
type of craft is that, unlike the airplane, its lift does not derive 
solely from its advancing through the air. Even if the engine 
stops, the rotor still revolves not enough to keep the autogiro 
aloft, but at least with sufficient lift to permit it to settle to 
earth slowly without a crash. 

Though it looks something like an autogiro, the helicopter, 
which also has rotating wings, is entirely different, for the rotor 


is continually driven. The rotor is a vertical propeller which 
pulls the machine straight up. Many unsuccessful attempts to 
make a helicopter fly preceded those of a few years ago which 
finally did it. In the United States, the first success was achieved 
by Igor Sikorsky, Russian-born inventor who has made his 
talents available to us for a number of years. 

Several problems had to be overcome in making a successful 
helicopter. For one thing, there was torque, or the tendency of 
the whole craft to spin in a direction opposite to that of the 
rotor. This is a result of the same effect that makes a gun kick 
the bullet is pushed forward, and the gun is pushed back- 
wards. The engine tries to spin the rotor around clockwise, let 
us say, but it is also trying to turn the fuselage around counter- 
clockwise. On the ground it cannot, because of the friction be- 
tween the landing gear and the earth, but in the air it can and 
will, unless something is done to prevent it. 

One solution is to provide two rotors, turning in opposite 
directions. These may either be one above the other or side 
by side. But that introduces complexities; and so Mr. Sikorsky 
put on the tail of his craft another, smaller rotor, spinning in a 
vertical plane, and in a direction to counteract the effect of 
torque. He was able to dispense with a third rotor, or propeller, 
to provide a forward pull. Instead, means are provided for 
tilting the main rotor in any direction. Tilting it forward, the 
helicopter advances. By tilting it backwards, the machine is 
made to back; similarly, it can move to one side or the other, 
or hover perfectly still in the air, even when only a few feet 
above the ground. In fact, one of the startling demonstrations 
that Mr. Sikorsky likes to put on is to hold the machine at this 
altitude while a mechanic calmly walks over and changes the 
wheels of the landing gear! 

For many helicopters, however, three inflated rubber spheres 
are used instead of wheels. These can be used for coming down 
practically any place on water, on rough rocks, or on top of 
a building, since the takeoff and landing may be really vertical. 

Like the autogiro, the speed of the helicopter is limited 


probably it could not do much better than a hundred miles 
per hour at best. But its great advantage lies in its ability to 
move through the air at much lower speeds, impossible for 
conventional airplanes. It is not likely to threaten their su- 
premacy for long-distance travel, where speed is desirable; 
but the helicopter may well make feasible an aerial taxi service 
taking an air passenger from the street in front of his home 
to the airport, for instance. And in addition it offers great pos- 
sibilities as a private aircraft for individuals. 


Most aircraft designers, especially those working on war 
planes, however, are still concerned with speed. Though actual 
records of the fastest are closely guarded military secrets, they 
have probably reached 500 miles per hour well above the last 
official record, established in 1939 by a German flier, of nearly 
470 miles per hour. No doubt, too, the latest ships can maintain 
their high speeds over considerably longer distances than the 
short courses over which such records were established. In at- 
taining such results many different researches were combined. 
Not only were the outlines of the planes made smooth and 
streamlined the metallurgist contributed the strong light 
alloys of which the framework and the shell is made. He also 
developed new alloys for the engine, which can be made light 
and strong, yielding a horsepower for every pound of its weight. 
The chemist contributed the 100-octane gasoline; and numerous 
special controls have been added to give accuracy and reliabil- 

Satisfactory operation of airplanes at great altitudes has be- 
come increasingly important, both for peace and war. Six 
miles up the air is steady, for this is above most of the weather, 
so cruising speeds of 300 miles per hour at such an altitude 
would be entirely practicable for commercial transport. For 
fighter planes, great altitude affords also the advantage that a 
pilot may be able to get above enemy craft. Such altitudes in- 


troduce new problems, one of which has been effectively solved 
by the turbosupercharger. But let the inventor of this device, 
Dr. Sanford A. Moss, General Electric engineer, and winner of 
the 1941 Collier award for great contributions to aviation, tell 
its story. He says: 

An airplane engine obtains its power from explosions of charges of 
gasoline and air, the major purtion of the charges being air. The air 
is obtained by being sucked in from the atmosphere as the engine 
pistons move back and forth. At altitudes above sea-level the atmos- 
pheric air gets thinner and thinner so that the charges being sucked 
in become less and less as airplanes fly higher and higher. 

During the last war it occurred to some engineers to push increased 
charges of air into airplane engine cylinders, rather than depend upon 
suction from the atmosphere. This was soon found possible, and so 
the supercharger came into use. 

The modern supercharger has a rotary wheel, called an impeller, 
of the same general nature as the rotor of a fan blower. However, the 
supercharger impeller rotates at a very much higher speed and has a 
more complicated design than any ordinary fan blower. This super- 
charger impeller is driven either by gears from the engine crankshaft 
or, in the case of the turbosupercharger, by a turbine wheel driven by 
the exhaust gases of the engine. The design of the impeller and its 
casing, the means of driving, the multiplication of effect by having 
several impellers in combination, and similar items, are technical 
details which have been the subject of great research, but which need 
not here be elaborated upon. The net result is compression of the 
atmospheric air at any altitude, so as to deliver an increased amount 
to the airplane engine. 

The effect of the supercharger in thus pushing an increased charge 
into the engine cylinder can be made of service in three ways: 

First: By maintaining the charge at the same amount as it would be 
at sea-level, as an airplane engine flies at increased altitudes. Other- 
wise the engine power would decrease in proportion to the decreased 
air density, so as to cut the power in half at about 20,000 feet altitude, 
with greater decreases at higher altitudes. 

Second: By increase in the amount of charge used by the engine at 
sea-level, so that a given engine will give an increased amount of 
power. This may vary from an increase of 25% or so for short inter- 
vals, to greater increases for longer times, depending upon the design 

Third: By a combination of these two items, so that at all altitudes 


an engine will give the same increased amount of power as was pos- 
sible at sea-level. 

During World War I, the possibilities of superchargers began to 
be developed, but none of them then reached actual use. After the 
war, supercharger research was continued, and about 1920 a number 
of sorts of superchargers began to be used to a small extent. This use 
increased to about 1925 when it began to be evident that the super- 
charger was worth serious attention. About 1930 practically all avi- 
ation engines had a geared supercharger built in as an essential part 
of the engine structure. Similar advances were made with turbo- 
superchargers driven by engine exhaust gases. About 1940 these 
turbosuperchargers were being used to a greatly increased extent in 
United States military planes. 

Every advance in the use of both geared and turbosuperchargers, 
obtained by engineering research, and by a practical demonstration 
of the results of this research, has given an appreciable increase in 
engine performance. As is always the case with every sort of engineer- 
ing research, this process will continue and new refinements, new 
extensions, and new principles will be introduced into the super- 
charging art. It seems certain, therefore, that supercharging of one 
sort or another will form a more and more important part of aviation 
progress, both for commercial and military airplanes. 

The exact nature of these expected refinements and extensions can 
hardly be predicted at the minute. Furthermore, even if they could 
be predicted, they would not pass military censorship. But it seems 
certain that the progress which has been made, from zero in 1918 to 
the very great use of superchargers in 1942, will proceed to an ac- 
celerated extent in the next quarter century. 

Of course, the supercharger is only one of the many sorts of things 
which are undergoing intensive development in aviation at the pres- 
ent time. All of these will result in increased performance of airplanes, 
and increased use, both from a commercial and military point of view. 

Modestly, Dr. Moss's account leaves out the part that he him- 
self played in this development. It does not tell how he was 
retired in 1938, to be called back two years later, nor how, in 
1918, he hauled a Liberty engine to the 14,000 foot height of 
Pikes Peak and found that it yielded only 230 horsepower, in- 
stead of 350 as at sea level. But when the turbosupercharger 
was cut in, 356 horsepower was obtained. With its aid, in 1920, 
Major R. W. Schroeder established a new altitude record of 


36,020 feet, to be broken the following year, by using the same 
device, by Lieut. J. A. Macready, with 40,800 feet. 

More recently the turbosupercharger has made possible the 
work of the U. S. Army's "Flying Fortress," which can attain 
speeds of better than 330 miles per hour at heights of six miles 
or more while carrying a heavy load of bombs. This is above 
anti-aircraft-gun range, and is so high that the bomber cannot be 
seen or heard from the ground. The bombs can be dropped 
with considerable accuracy, thanks to the steadiness of flight 
at these heights, and the plane can be off before the inter- 
ceptors have been able to climb to its level. 

Like so many war-inspired developments, this too will have 
important applications in peace, as Dr. Moss intimated. Instead 
of bombs, commercial planes flying at such speeds and levels 
will be able to carry large numbers of passengers, great loads 
of aerial freight or large quantities of gasoline for long-distance 
non-stop flights. And to permit the crew and passengers to sur- 
vive at heights of even ten miles, the sealed cabin itself will 
be supercharged, keeping the air pressure of much lower levels. 
Indeed, this was lately done with the TWA "Stratoliners" plying 
between New York and Chicago; civilian versions of the Flying 

It is not only the plane itself which determines its perform- 
ance. Although, as planes become more and more reliable, they 
are able to withstand conditions disastrous for earlier models, 
weather is still a factor for lower-flying planes; and even the 
ships plying in the sub-stratosphere have to pass through these 
layers on their way up and down. Accurate forecasting enables 
fliers to know what conditions they may encounter; but still, 
as always, there is not much that we can do about the weather. 

Fog is one of the greatest dangers to aviation, but inventive 
ingenuity has made possible looking through it; a necessary 
development, since it is hardly practicable to remove fog over 


a large area. In small lots it can be removed. If, for example, 
the air is heated, the fine droplets of water of which the fog is 
made may evaporate. Or calcium chloride solution can be 
sprayed into the fog. This absorbs water from the air, which 
becomes drier, so the fog particles can evaporate without an 
increase in temperature. Intense sound waves have been used 
to precipitate smoke, and might do the same on some kinds of 
fog, by causing many droplets to coalesce until they are big 
enough to fall to the ground. 

Aerial photographs from great altitudes have been made 
with infrared light, showing details hundreds of miles away as 
clear as those much nearer. Yet with ordinary light photographs 
the distance is completely obscured in haze. Such experiments 
have led to a common idea that infrared rays can look through 
fog. A device has been constructed for taking photographs on 
special film in infrared light and developing it immediately and 
automatically, with the thought that it might be placed on the 
bridge of a ship, so that the pilot could make port in foggy 

The main trouble is that infrared rays do not penetrate fog. 
As Dr. Sverre Petterssen, professor of meteorology at the Massa- 
chusetts Institute of Technology, said in a lecture to the In- 
stitute of Aeronautical Sciences: "There is no region of the 
radiant energy spectrum which will penetrate fog better than 
visible light. This result has been confirmed by direct measure- 

The common belief that infrared rays do go through fog 
better was based partly on photographs showing their superior 
penetration of haze, and partly on the misuse of a formula for 
the transmission of light through suspended particles. This 
formula applies only if the particles are of about the same size 
as wavelengths of light, which the haze particles actually are. 
However, fog particles are some five hundred times bigger 
each about 0.06 inch in diameter and light waves equally long 
would have to be used to produce an effect. But though waves 


as long as this may penetrate the fog, they in turn are absorbed 
by the gases of the atmosphere; so their advantage would be 

But even though they cannot penetrate a dense fog, infra- 
red rays have important possibilities. One is the detection at 
night of enemy aircraft or ships that approach in darkness 
and are not considerate enough to provide lights or to warn 
of their coming. Infrared rays are given off by any hot object. 
Hold your hand near a flat-iron that is in use, and you can feel 
them, even though you cannot see them, because they are 
made of waves too long for the eye to detect. The hot cvlinders 
of an airplane engine, or the hot funnels of a steamer, give them 
off copiously. So does the mass of hot gases exhausted from 
either type of engine. 

Since infrared rays are like light waves, they may be fo- 
cused, either with lenses or with concave mirrors, and an image 
formed of anything which is emitting or reflecting them. Some 
means must be found to make this image visible, and fortu- 
nately there are several ways of doing it. One, devised by 
Dr. V. K. Zworykin of the Radio Corporation of America, whose 
work with the electron microscope will be described in the next 
chapter, invented a means of doing it with electrons. A lens 
forms an infrared image on a thin metal plate which is coated 
with a compound of silver, caesium and oxygen. Where the rays 
fall on such a film tiny bits of atoms called electrons are dis- 
charged. These in turn can be focused with an electron lens 
one kind consists of a circular electromagnet on a glass 
screen coated with a fluorescent material. This glows where 
electrons strike, and the picture then becomes visible. 

A still simpler means of making visible an infrared image 
was invented by Roscoe H. George, assistant professor of elec- 
trical engineering at Purdue University. 1 His discovery grew 
out of the observation that certain substances, related to those 
with which the final screen of the Zworykin infrared telescope 

1 Rights on the U. S. Patent ( No. 2,225,044 ) granted him in December, 1940, 
are held by the Radio Corporation of America. 


was coated, are phosphorescent. That is, they continue to glow 
for a time after they have been excited with light either visible 
or in the ultraviolet range, the waves of which are too short 
to be seen. Electrons and X-rays can also excite phosphores- 
cence; and phosphorescent materials store energy, then give it 
off again later. But if they are sprayed with infrared rays they 
give it off more quickly. That is, you can take a phosphores- 
cent screen out into the sunlight, expose it, then bring it into a 
darkroom, and it will be seen to glow. But if, in that darkroom, 
you have a source of infrared and hold the screen in its beam, 
it glows more brightly, but for a shorter time. 

In Professor George's invention, the idea is to focus the 
infrared rays from the distant source, such as the plane's ex- 
haust gases, on a phosphorescent screen with a concave mirror. 
It operates like an astronomer's reflecting telescope. Inside the 
telescope is a source of invisible ultraviolet, which shines on the 
screen and makes it glow faintly. Where the infrared rays fall, 
it glows more brightly, and the image is made visible. 

In the formal language of the patent specifications, the use 
of the detector was described thus: 

The present invention is useful in ascertaining the position of air- 
planes at night . . . since a certain amount of infra-red light is radi- 
ated from the exhaust manifolds of an airplane engine and this infra- 
red light is sufficient in intensity to make the position of the airplane 
visible through the use of the present invention even though the air- 
plane itself is invisible, when the present invention is not used. 

Infrared rays will not penetrate fog, but ultrashort radio 
waves, many times longer still, will do so. There are various 
ways of producing such waves; one is with the klystron, de- 
veloped in the physics laboratory of Stanford University by 
Sigurd and Russell Varian. 2 Another is the magnetron of Dr. 
A. W. Hull, of the General Electric Research Laboratory. These 
are of the order of frequency of 600 megacycles or about 20 
inches in length, far below any used regularly in broadcasting. 
They have many of the properties of light waves; they can be 

2 Further work with it has been done by the Westinghouse Company. 


focused in a beam like that from a searchlight. And just as light 
waves are reflected and sent back, so these are reflected, par- 
ticularly by a metal object such as an airplane. 

It is by the use of such waves that, as the Roberts report 
revealed, the Japanese bombers that attacked Pearl Harbor on 
December 7, 1941, were detected when they were 130 miles 
away. It was not the fault of the apparatus that its indication 
was ignored. No present-day military device is kept more care- 
fully secret than the details of this equipment, just what is in 
it, and how it functions. However, enough has been revealed 
from official sources to get a general idea of the fundamental 
principles. In February, 1941, for instance, a patent (No. 2,231,- 
929 ) was granted to Joseph Lyman of the Sperry Gyroscope Co. 
and, like all patents, was published by the U. S. Patent Office. 
"The novel indicator," the inventor stated in the specifications, 
"is adapted for use on aircraft either for indicating the direction 
of approach of other aircraft, to thereby prevent collision under 
conditions of poor or zero visibility, or for use on the ground as 
when locating aircraft for purposes of gunfire control, or for 
controlling aircraft landings from the ground, and for other 

One form of detector which was suggested used a radio 
"searchlight." A motor would be arranged to move it around, 
and up and down, so as completely to sweep the sky. When it 
encountered some reflecting object, such as an airplane, the 
waves would be sent back and picked up by a receiver. The 
echo returns practically instantaneously; and it might indicate 
by an electron beam on the end of a television picture tube. 
The electron beam would keep in step with the swing of the 
searchlight, increasing in intensity and making a bright spot 
when the echo was heard. Thus, the position of the spot on the 
screen would show the direction of the plane. 

Another form suggested by Mr. Lyman makes use of two 
sheets of radio waves. One would always be vertical, and would 
sweep around the horizon. The other would at one moment be 
horizontal, then would sweep up to a vertical position and down 


the opposite side. The connections on this device would be 
arranged so that both sheets of waves would act together, and 
their intersection would take the place of the single beam in 
the other locater. 

Though developed for wartime use, such a locater obviously 
has tremendous possibilities for peace-time flying. Already, in 
fact, the Bell Telephone Laboratories, in co-operation with 
United Air Lines, have devised a terrain-distance indicator. 
The ordinary altimeter, which simply measures air pressure, 
tells the height above sea level; but more important to the pilot 
is his distance above ground. Ships at sea make use of a sonic 
depth-finder to tell the distance to the ocean bottom a series 
of sound waves are sent downwards and the time of their return 
measured. The terrain-distance indicator works in a some- 
what similar way, but radio waves take the place of sound. It 
makes its measurements of time by the interference which the 
returning waves make with those starting off; and it is so 
precise that, from a mile high, the aviator can tell the height 
of a building below him. 

With such an indicator pointed ahead, he would be warned 
of approach to a mountain side, for example. But if the plane 
has a radio detector aimed forward, he might be able to see 
the outline of the mountain, and even to find in a dense fog a 
safe opening between two peaks. 

These are some of the possibilities of aviation in our post-war 
world. Thousands of men, and women too, are trained as pilots, 
or as operators of all these aids to aviation. Their equipment is 
ready, factories are turning out planes in enormous quantities; 
and certainly it seems reasonable to suppose that what aviation 
did in the 1918-1939 period of peace will be considered trifling 
compared to the developments that are at hand. 

XIV. The Age of Electrons 

It was in the year 1895 that a bearded German professor of 
physics at the University of Wiirzburg saw a shadow, which 
ushered in the age of electrons. This discovery by the Herr 
Professor made possible the first of a long line of practical ap- 
plications for man's benefit, including such devices as X-rays, 
the radio, the electric eye, sound movies, and a host of others. 

The shadow that Wilhelm Konrad Roentgen saw extended 
across a card coated with white material. Now there was no 
reason why a shadow should not have fallen across this card, 
except that there was no light to make it. 

About a score of years earlier, Sir William Crookes in Eng- 
land had experimented with high-voltage electric currents sent 
through glass tubes from which the air had been mostly ex- 
hausted. Such tubes are still called "Crookes tubes/' From one 
of the electrodes inside such a tube, he found, mysterious rays 
were given off. As these came from the electrode called the 
cathode, they were named cathode rays; and by an application of 
these, certain minerals sealed inside a Crookes tube were 
made to glow with beautiful colors. From a concave cathode 
the rays could be focused on a piece of platinum foil, which 
then glowed at red heat. A little "windmill" with featherweight 
vanes was set in rapid motion when the rays fell upon it. 

To explain the rays Crookes suggested a "fourth state of 
matter," different from the known solid, liquid and gaseous 
states. The study of these effects became a most popular field 
of research, and many new facts were uncovered. Heinrich 
Hertz, better known for his discovery of the "Hertzian" waves 
which form the basis of radio, found in 1893 that thin pieces of 
metal such as aluminum, when placed in a Crookes tube, were 
penetrated by the rays. Philip Lenard, the following year, car- 



ried this discovery further: he made an aluminum window in 
one of the tubes and obtained the rays in open air. 

Roentgen was working along similar lines in 1895. In the 
course of his studies he had tubes of various kinds. Some were 
pear shaped, with the cathode at the small end. The rays were 
sprayed toward the large end, and they caused the glass to glow. 
To hide this glow, Roentgen had covered some of the tubes 
with black paper. Also he frequently used a piece of cardboard 
coated with barium platino-cyanide. The cathode rays that 
Lenard had obtained in the open air caused this chemical to 
glow with a greenish-white color. 

On one memorable day Roentgen was working with such 
material. It happened that the iron rod of an apparatus sup- 
port stood between the tube and the cardboard screen lying on 
the table. There, across the screen, extended a shadow of the 
iron rod, even though no light was shining on it which could 
cause such a shadow. Later, someone asked Roentgen what he 
thought when he saw this strange shadow. His answer ex- 
pressed the true scientific spirit. 

"I did not think, I investigated," he said. 

As a result of his investigations over the next few months 
Roentgen was able, in December, 1895, to report to the Wiirz- 
burg Physical and Medical Association his discovery "Of a New 
Kind of Rays/' as he expressed it in the title of his paper. Not 
knowing what these rays were, he called them X-rays, "X" 
being the mathematical symbol for the unknown. Paper, wood, 
hard rubber, he found, were transparent to the rays; so were 
thin metallic sheets except lead, which was opaque, as were 
greater thicknesses of other metals. He recognized that these 
rays were not the same as the cathode rays, though thev were 
produced when those rays struck the glass walls of the tube. 
Also, he found that other materials inside the tube, such as 
metal targets, acted as a source even better than the glass. 

Photographic plates were affected by the rays, so by means 
of them it was possible to make radiographs. Since the bones are 
more opaque to them than the flesh, the X-rays gave a means of 


recording on the photographic plate, as well as viewing on a 
screen, the skeletal framework of the body. With every well- 
equipped physical laboratory already provided with one or 
more Crookes tubes and the spark coils to make high voltage 
to run them, Roentgen's experiments were being repeated just 
as soon as the newspapers could carry the word to an excited 
world. And also, more than one physicist felt a pang of regret 
at the great discovery that he had missed. For example, Crookes 
himself had been troubled by a mysterious fogging of his well- 
wrapped photographic plates when he operated some of his 
tubes in their neighborhood. A prominent American phvsicist 
had even, inadvertently, made a radiograph several years be- 
fore Roentgen's discovery. 

This near-discovery came in the course of some experiments 
in photographic electrical discharges. Metal discs, connected to 
the source of high voltage, were placed on photographic plates, 
and in this work the American had the help of a photographer 
friend. One evening, after they were through experimenting, 
the physicist demonstrated to his friend some of the Crookes 
tubes in his laboratory. Near by lay the box of plates, the metal 
discs on top. When the plates were developed, it was found 
that they showed images of the discs actually an X-rav pic- 
ture, made through the cardboard box. But puzzled though they 
were, neither could explain what had happened. Not until 
Roentgen announced the discovery of X-rays did the physicist 
realize what a close approach he had made to achieving world 

At this same time many other scientists were hard at work on 
the problem of what the cathode rays really were. When, in 
1897, J. J. Thomson, the young director of the Cavendish Lab- 
oratory at Cambridge University, demonstrated that the rays 
could be deflected both by electrical charges and by mag- 
netism, it became evident that the rays consisted of streams of 
particles at least a thousand times lighter than the hydrogen 
atom. Since they came out of many different substances used 
as a cathode, it seemed as if they might be a common constitu- 


ent of all these materials. Of all the elements, the atom of hydro- 
gen was supposed to be the smallest, and, people believed 
equally firmly up to that time, the atom was a solid entity, 
incapable of further division. 

Yet Thomson's results were confirmed by others, and the 
electron, as the new particle was called, took its place as a unit 
of which atoms are made. Though its size cannot be stated with 
certainty, crude assumptions lead to the conclusion that some 
twenty-five trillion would have to be lined up in a row to equal 
an inch. 

Atoms have been pictured as being made up of electrons whirl- 
ing in orbits around a central nucleus. Each electron has a nega- 
tive electrical charge, and in the nucleus is a positive charge cor- 
responding to each of the orbital electrons. This picture shows a 
strong resemblance to the solar system, with the planets moving 
in orbits around the central sun. There is another resemblance, 
too. Just as each planet is spinning on its axis, so the electrons 
are supposed to be spinning. A spinning electrical charge pro- 
duces the effect of magnetism, and in the spinning of the elec- 
tron we find the basis of magnetic effects. 

So, all matter is made ultimately of electrical charges. But 
not only are there the electrons in the atoms. In a metal, for 
example especially one that is classed as an electrical con- 
ductor, like copper there are so-called "free" electrons floating 
around between the atoms; and these apparently are respon- 
sible for conduction of electricity as they flow along the wire. 

All this seems of very little practical value, and one might 
sympathize with the wealthy donor of a physics laboratory in 
the early days who, when shown some of these electrical dis- 
charges, remarked, "How beautiful, and how useless!" 

However, the clue to the utility of the electron goes back 
somewhat earlier, to none other than Thomas Alva Edison. In 
1883, in the course of his experiments with the electric lamp, a 
blue glow appeared when he sealed a small metal plate in a 


bulb with the lamp filament. A wire led from this plate to the 
outside. When the lamp was turned on, Edison found that there 
was, in addition to the current which he put in to light the 
filament, another and very mysterious current flowing between 
one of the filament wires and the wire from the plate. In other 
words, this current flowed across the evacuated space in the 
bulb. Thinking it might have some utility, he patented it; but 
the patent had expired before the effect was explained, much 
less applied. 

After Thomson's discovery of the electron in 1896, it became 
apparent that this is responsible for the Edison effect. As a re- 
sult of the heating of the filament, some of the electrons it con- 
tains are freed and float away. Since these electrons are the 
same agents that carry a current through a wire, it is not sur- 
prising that they can carry a current across the vacuum in the 
bulb. That is, a minute electron current can be detected be- 
tween the plate and the positive side of the circuit which lights 
the filament. This, however, is very slight, and a delicate in- 
strument is needed to measure it. If, on the other hand, a bat- 
tery is connected in this plate circuit, a larger current flows if 
connections are right; and the stream of electrons may be made 
to serve as a switch. Wlien the filament is cold, none flow 
the switch is off. But when the filament is lighted the electrons 
start flowing the switch is on. When a rheostat is connected 
to the filament circuit, so that it can be turned up and down, 
the electrons vary and the plate current changes in step with 
the current to the filament. That is, it does up to a certain point; 
for when the current is pulling all possible of the escaping elec- 
trons across the gap, saturation is reached, and no more can 
be carried. 

It was stated that the battery, in the plate circuit, had to 
be connected the right way. The plate has to be connected to 
the positive pole of the battery the other way will not work. 
That is, the discharge of electrons from filament to plate is a 
one-way street for electricity. 

In the early radio receiving sets, crystal detectors were used, 


consisting of a bit of galena, or some similar mineral, on which 
a thin wire, or "cat's whisker," lightly touched. This also lim- 
ited the electrical traffic to one way. The electrical waves, vi- 
brating back and forth, which came into the receiver from the 
antenna, were rectified, and only those going in one direction 
got through and operated the head phones which radio listen- 
ers of those days had to use. 

As long ago as 1904 J. A. Fleming, an English scientist, ap- 
plied the Edison effect in a rectifier tube. It was used for radio 
reception, and also in other electrical equipment that required 
it. For instance, the ordinary lighting circuit of our houses is 
alternating current; the direction of flow of the current changes 
sixty times a second. Often it is desirable to change this to direct 
current, with the flow always in the same direction. By using 
a single Fleming valve (as such a tube was called in England 
because it did to electricity what a valve does to a flow of liquid 
or gas) only current in one direction can get through. That 
flowing the other way is blocked and wasted; but by using two 
such valves, properly connected, the opposite flow can be 
turned around, and then the wasted half is utilized. 

Such tubes, generally called "diodes," are widely used today 
for rectifying. But the familiar tubes in our radio sets are "tri- 
odes," at least, for they contain another very important element 
the "grid." 

This was the invention of another American, Lee de Forest, 
in 1907. Between filament and plate he inserted a small screen, 
or grid, of wires. This can be thought of as a Venetian blind. 
Positively charged, the same as the filament, the blind is open 
and electrons pass through freely. But if it is gradually made 
negative, this is equivalent to closing the blind; and the stream 
of electrons is reduced and finally stopped. Such tubes made 
possible a new function that of amplification. A very small 
current on the grid can control the flow of a larger current 
through the tube and, because of the instantaneous response, 
the quickest variations in the grid circuit are immediately re- 
flected in the flow from the plate. 


However, such tubes were seriously limited. They had to be 
operated with a relatively low vacuum, otherwise they would 
not pass a current. And the voltage had to be low, not over 
thirty or forty, otherwise Edison's blue glow appeared; the tube 
became erratic in behavior and soon went bad. The generally 
accepted theory was that the filament would not emit electrons 
unless some gas was present; and that seemed to impose a limit. 

Dr. Irving Langmuir, in the General Electric Research Lab- 
oratory, had other ideas. Already, for his experiments on the 
cause of the blackening of incandescent lamps, he had de- 
veloped equipment that would give and would accurately meas- 
ure a vacuum higher than had been reached before. So now he 
used it to investigate the way electrons come from a filament. 

Langmuir discovered that a filament will emit electrons in 
the very highest vacuum; but these electrons give the actual 
space around the filament a negative charge. Since like charges 
repel each other, this space charge repels additional electrons, 
each of which also has a negative charge, and they are pre- 
vented from doing their task. Langmuir found that when a small 
amount of gas is present, the electrons knock off other electrons 
which were part of the gas atoms. The remaining pieces, or 
"ions," have positive charges and neutralize the interference of 
the negative space charge. 

Having found the cause of the difficulty, Langmuir was then 
in a position to overcome it. The plate of the tube was placed 
as close as possible to the filament; then, by using a higher volt- 
age than had been possible before, electrons were pulled across 
the space so quickly that they were not there long enough to 
produce a space-charge effect. He could use a high voltage be- 
cause, with high vacuum, there was no longer a blue glow to 
set a limit. 

This discovery made it possible for the first time to design 
and build tubes which could handle high power tubes in 
which the feeble currents from a microphone, for example, 
could be amplified millions of times built up to 100,000 watts, 
or even more, to be used in powerful short-wave radio transmit- 


ters that send clear signals to distant lands. Radio broadcasting 
would not have been possible without the electron tube and 
this means of using high power; for the inefficient spark trans- 
mitters of the earlier days of wireless telegraphy are quite im- 
practicable for faithfully reproducing voice and music. 

What happens in transmitting tubes, some of which handle 
a quarter of a million watts of power, is comparable to an an- 
noying prank you could play with the older telephone desk set 
with a separate receiver. When the receiver was held against 
the transmitter, there was an unearthly howl. Sound waves from 
the receiver fed into the transmitter, were carried, as electrical 
impulses, back to the receiver, started around again, and so 
on, building up the oscillations. 

In a radio transmission tube, part of the current from the tube 
is sent back to its own grid, and analogous electrical oscillations 
are started which eventually travel out from the antenna of the 
station. Receiving tubes, some with even a fourth or a fifth 
element as additional grids, are used in modern radio sets. Con- 
stant research has shown how to get the greatest flow of elec- 
trons by using, for instance, not a filament of one wire as their 
source, but a small nickel cylinder, coated with the oxides of 
barium and strontium. Inside the cylinder is a filament to 
heat it. 

Many of the vacuum tubes used in present-day radio sets are 
made of metal instead of glass. However, glass is still needed 
inside to insulate the various wires. Research in the General 
Electric Research Laboratory made this possible by the de- 
velopment of alloys of iron, nickel and cobalt which expand 
when heated and contract when cooled at just the same rate as 
the glass. If the expansion and contraction rates were different, 
of course, a glass-and-metal seal that was tight when the tube 
was cold would loosen and let air in as it heated in use. 

Perhaps the most amazing thing about the modern vacuum 
tube is the application of mass-production methods to its manu- 
facture, to supply the millions that are needed annually at low 
prices. Today, for less than a dollar, it is possible to purchase 


a vacuum tube which is far more efficient than one which cost 
many dollars only twenty years ago when broadcasting made 
its debut. 

Another electron tube has found application in such varied 
tasks as controlling the lighting for a dance number on the stage 
of the Radio City Music Hall and welding the metal shell of a 
bombing plane. This is the thyratron. In one of its largest sizes, 
it will control 300,000 watts of power with less than half a watt 
applied to its grid! 

Different from the thyratron, which contains gas, is the high- 
vacuum kenotron, which operates over a range from a few 
volts to several hundred thousand. Its chief application is in 
rectification that is, in converting the alternating current pro- 
duced at most power stations into the direct current needed for 
such applications as the operation of X-ray tubes. Even this 
does not complete the family, for there are also the pliotron, the 
magnetron, and hundreds of other types of electron tubes, each 
with particular applications. 

Of particular importance is the photoelectric cell, which, in 
its various modifications, sorts cigars, makes sound movies and 
television possible, opens and closes doors in stations and res- 
taurants, turns on lights in schools, acts as a burglar alarm, and 
measures the brightness of stars. Its story again takes us back 
to Heinrich Hertz. 

In 1880 Hertz was engaged in experiments with electric 
sparks. These were high- voltage discharges across open gaps; 
and he was surprised to find that when an arc light was shin- 
ing on a gap, the same voltage would cross a longer distance 
than it would in the dark. Some time later W. Hallwachs found 
that a clean zinc plate, connected to an electroscope a device 
for detecting electrical charges lost its negative charge when 
the arc light was shining on it. But the arc had no effect if its 
light had to pass through a piece of glass. Since it was known 
that the light of the arc contained ultraviolet rays, waves too 


short to be visible, it seemed evident that they were respon- 
sible, and that, in some way, they pulled negative charges from 
the zinc. 

It turned out that zinc, under the influence of light, emits 
electrons "photoelectrons," they are now called. Metals vary 
in the extent of this electron emission. Caesium and potassium 
have been found to work especially well, particularly with visi- 
ble rays of light. The explanation of the details by which the 
photoelectric effect takes place was of great importance in scien- 
tific history. It was given by Albert Einstein, and won for him 
the Nobel Prize in Physics in 1921. Even if he had never thought 
of the theory of relativity, this accomplishment would still be 
enough to give him a prominent place on the roster of great 
scientists. It confirmed the quantum theory, proposed earlier 
by Max Planck, which states that light, and other forms of 
radiation, do not travel in a continuous stream of waves, but in 
little bunches, or "quanta." 

The modern photoelectric cell has a metal surface, coated 
with caesium or a similar metal, in a glass bulb which is evacu- 
ated or contains an inert gas. The metal surface is one of the 
electrodes to which connections are made, and the other is a 
metal wire. When light falls on the caesium, it becomes capa- 
ble of liberating electrons. If it is connected with a source of 
current, electricity can flow in the direction that the electrons 
travel. The result is comparable to the original Fleming valve, 
where heating of the filament made the tube a conductor. In 
the case of the photocell, light falling on the coated surface 
has the same effect. As current from the cell may be rather 
weak, it is often fed into a triode, or even a series of them, or 
into a thyratron, to enable the photocell to control much larger 
amounts of power than it can directly. 

A development of recent years is the electron-multiplier 
tube. EssentiaUy, this is a combined photocell and multi-stage 
amplifier all in one glass envelope. The photoelectrons from 
the original sensitive surface strike a second plate, which is also 
an excellent emitter. Each electron striking it may release half 


a dozen more. These strike a third plate, and again the yield is 
multiplied hence the name of the tube. With as many as a 
dozen steps in a single tube, the amplification may amount to 
hundreds of millions of times. 

For many purposes another form of light-sensitive device, 
called the photovoltaic cell, is used. In one form this consists 
of iron coated with a layer of selenium, and on top is a thin 
layer of gold. When light strikes, electrons pass from the lower 
to upper layers and there is a flow of current. Thus, these cells 
actually generate electricity without the need of an external 
battery. For this reason they are used in popular types of 
photographic exposure meter, such as the General Electric and 
the Weston. With enough cells, sufficient current can be gen- 
erated to run a small motor. Perhaps the day will come when 
sun-drenched desert areas of earth will be covered with such 
cells, turning light into electricity for the use of the world. 

For opening doors, as in the Pennsylvania Station in New 
York, a beam of light is sent across the passageway through 
which people must pass. This falls on a photocell, and the cur- 
rent, amplified, operates a magnet which holds down a little 
lever a common device, called a relay. When the light is in- 
terrupted, the current stops, the lever is pulled by a spring, and 
it makes contact to close a second electrical circuit. This in 
turn operates the motors which open the door. The same 
method can be used to count the number of visitors entering 
a museum. In this case the lever, each time it is released from 
the magnet (or alternately, with a different connection, each 
time it is pulled toward it ) , operates a counter. 

The device may even be made to exercise judgment! That is, 
it can count people going in, but pay no attention to those go- 
ing out. This is done by two light beams, two photocells and 
two relays. The inner beam operates a relay which disconnects 
the counter, so if that operates first nothing happens. But a per- 
son coming in interrupts the other beam first, and the counter 
operates before the other beam is broken. Photocells have also 
been used to inspect cigars, oranges and a variety of other 


things. The articles to be inspected pass on a belt under a strong 
light, which they reflect to a photocell. When one comes along 
that is too light or too dark, more or less than the normal light 
falls on the "electric eye." Either occurrence may operate the 
relay; and another lever, magnet-operated, kicks the offender 

Because the photocell is so sensitive, and because its cur- 
rent, proportional to light falling on it, can be measured so 
accurately, it has become a powerful aid to the astronomer in 
measuring the brightness of stars. Another astronomical use 
that is just beginning is in guiding star cameras on long ex- 
posures. On account of the changing path of the light through 
the earth's atmosphere, caused by irregularities of temperature, 
it is customary for an astronomer to sit constantly at such a 
telescope while a picture is being taken with an exposure, per- 
haps, of many hours. But experiments at the California Institute 
of Technology, which will operate the new 200-inch telescope 
to be ready in a few years on Mt. Palomar, indicate the pos- 
sibility of doing this by photocells. 1 

We have seen how light, and other forms of radiation, can 
set electrons into motion. The reverse process can take place, 
and moving electrons can start radiation. This, indeed, is what 
happens in the X-ray tube. 

After Roentgen's discovery, scientists puzzled over the nature 
of X-rays. They suspected that they were similar to light waves 
but shorter, even far shorter than the ultraviolet. If such were 
the case, it should be possible to "diffract" them. This can be 
done with light, using a piece of glass ruled with thousands of 
parallel lines to the inch. It acts in a manner similar to a prism, 
and breaks up white light into the colored band of the spectrum. 
With the wavelength of X-rays so much less, the grating needed 

1 The use of photocells in television and in sound movies is described later, in 
connection with those topics. 


to break them up and cause diffraction would have to be ruled 
with lines far closer than man could make. 

But there proved to be natural gratings of the requisite fine- 
ness. Prof. Max von Laue in Berlin, in 1912, made the sugges- 
tion that regular layers of atoms in a crystal, such as diamond 
or rocksalt, might serve as such a grating. When the experi- 
ment was tried, shooting X-rays through a crystal to a photo- 
graphic plate, spots caused by the diffracted rays were found 
around the central beam, and their position depended on the 
wavelength of the X-rays. This was using the crystal to study 
X-rays. About the same time Sir William Bragg, and his son 
Prof. W. L. Bragg, worked the other way and used X-rays to 
study the structure of crystals. 

From this pioneer work of the Braggs came an entirelv new 
means of determining the structure of matter. In many indus- 
trial laboratories today, X-rays are used in special X-ray spec- 
trometers to look into the construction of matter; of alloys for 
bombing planes, of fibers of wool and other textiles, and even 
into the behavior of rubber and of lubricating oil. 

X-rays, it thus turned out, are a form of radiation like light, 
which results when speeding electrons are suddenly stopped 
against a metal target. In early tubes the electrons were pulled 
from the cold cathode by the bombardment of positive ions. 
These ions were fragments of the molecules of the small amount 
of gas remaining in the tube, broken off, or "ionized," when the 
high voltage was applied. The rays were very erratic in behavior 
because of the difficulty in controlling accurately the minute 
amount of remaining gas. Then, in 1913, Dr. William C. Cool- 
idge, at the General Electric Research Laboratory, invented 
the tube now almost universally used which bears his name. 
Gas is all but completely removed. Electrons are supplied not 
from a cold cathode but from a small glowing filament like that 
of an electric lamp. High voltage is applied, as in the old tubes, 
and these electrons are pulled along and thrown with great 
speed against a target of metal, usually tungsten, from which 
the X-rays radiate. 


To get more and more penetrating X-rays, voltages were in- 
creased; but there proved to be a limit. If the voltage gets too 
high up to several hundred thousand or more, far above that 
needed for ordinary medical X-rays "field currents" appear 
in the tube. These are produced by electrons torn out of the 
cold metal. They make the tube erratic, may even cause its de- 

Over a decade ago, Dr. Coolidge found that these field cur- 
rents can be eliminated if the high voltage is applied in steps. 
Tubes were built in several sections, perhaps a hundred thou- 
sand volts being put into each one. If there are five sections 
each having this voltage, the electrons, after passing all the 
way through, will possess as much energy as if the total 500,- 
000 volts had been applied at once. 

Using this principle, about ten years ago Dr. Coolidge and 
Dr. Ernest E. Charlton developed equipment for 800,000 volts. 
It was made for a hospital, to give high-power X-rays for cancer 
treatment. The tube was 14 feet long and a foot in diameter. 
Because of its bulky high-voltage generator, a special building 
had to be erected to house it. Still bigger is a 1,400,000- volt 
X-ray outfit built by G. E. for the National Bureau of Standards, 
as shown in the illustration. And again electronic research, 
under the direction of Dr. Charlton, solved the problem of mak- 
ing million- volt X-rays portable. Paying tribute to him and his 
associates, Dr. Coolidge has said: "The research work involved 
occupied the full time of an average of six men for a period 
of four years, and this, starting of course not from scratch, but 
with full knowledge of the X-ray equipment of the prior art." 

Two developments were mainly responsible for the new unit. 
Enclosed X-ray equipment had previously used oil in the cas- 
ing to insulate the parts from high voltages. Now it was found 
that Freon gas, developed for use in electric refrigerators and 
known chemically as dichlordifluormethane, could be pumped 
in under pressure and was more effective Also, a new type of 
transformer was designed by W. F. Westendorp. This is called 
the resonance transformer; it eliminates the iron core that nor- 


mally forms the center of the coils of wire. With the core gone, 
the multi-section X-ray tube itself, 30 inches long and 3% inches 
in diameter, was placed in this central position, an advanta- 
geous one making for compactness and shortening the electrical 

A metal extension of the tube projects two feet from the cylin- 
drical tank which holds the entire equipment, and from its end 
emanate the X-rays. Some shoot straight ahead, as from a gun, 
others are sprayed to the side. Ordinarily direct rays are used, 
but sometimes the side ones are more convenient. The snout 
can be placed at the center of a boiler and a series of radio- 
graphs, as the X-ray pictures are called, taken with a single ex- 
posure on a series of films all around the circumference. In 
this way the new apparatus speeds inspection of machinery 
parts. The million-volt outfit will radiograph through five 
inches of steel in two minutes. A tube operating on 400,000 
volts, the next size smaller, requires three and a half hours for 
the same job. Even then, the lower power picture does not 
show nearly so much detail in the thicker sections. 

When a steel casting is found to have a defect, such as an 
inclusion of slag, the radiograph shows its position; the casting 
is sent back to the foundry and the defect is chipped out. Then 
new metal is welded in and the part is again X-rayed. If satis- 
factory, the construction of the machine is completed. 

Even on smaller parts, high-voltage is a help, as the tube can 
back away from the job and spray a large area with the rays. 
Don M. McCutcheon, in charge of the X-ray laboratory at the 
Ford Motor Company, found, with a heavy part destined for a 
large bombing plane, that at least six exposures were needed 
for each casting with 400,000 volts, while the million-volt ma- 
chine completely X-rayed six entire castings at once! 2 

2 Million-volt X-rays were not developed because of urgent wartime activities, 
but their application has been speeded. A present-day parallel is seen to the way 
in which the last war made popular the general use of medical X-rays. They still 
were somewhat of a novelty in 1914, but doctors called to military service had to 
use them. They learned their advantages, and continued to use diem in private 
practice after the war. 


Not only are the X-rays used in this way, and for examining 
the structure of matter by means of the X-ray spectrograph; 
the electrons themselves have similar ability. For example, in 
the General Electric Laboratory, the Bell Telephone Labora- 
tories and others, are used electronic-vacuum cameras that 
photograph the crystalline make-up of substances the thickness 
of which is measured in millionths of an inch. The camera is 
employed, for instance, to study deposits on the surface of 
metals, such as tarnish, polish, lubricants, and the first stages 
of corrosion. Where the X-ray apparatus works on thicker speci- 
mens, the electronic- vacuum camera supplements it by reveal- 
ing the nature of thin materials in a record that shows a series 
of concentric circles their spacing and position telling the sci- 
entist the arrangement of the atoms. 

The camera in the G-E laboratory is a brass tube about 
three-and-a-half feet long, combined with a focusing magnet. 
A beam of electrons, with a 40,000-volt push, enters one end of 
the tube. The magnet focuses this beam on the specimen, which 
is suspended inside. Here the beam is "diffracted" and the elec- 
trons paint their picture on a sensitive photographic plate at the 
other end. The brass tube has to be evacuated otherwise the 
electron beam could not pass through freely because of the col- 
lisions with air molecules. In sodium chloride common salt 
the layers of atoms are spaced one one-hundred-millionth of an 
inch apart. But the electron picture of this spacing shows a cir- 
cle an inch in diameter. 

It must not be supposed, however, that this gives a realistic 
picture of the arrangement of the atoms magnified a hundred 
million times. The resulting circle bears no resemblance to the 
appearance of the salt crystal. The effect is analogous to that, 
mentioned above, by which light is diffracted by a grating made 
of fine lines ruled on glass. 

This electronic diffraction method represents a very rapid 
application of fundamental research. The quantum theory, and 
the phenomena of photoelectricity, had shown that light, once 
thought of as a wave motion, had some of the properties of 


separate particles. In 1925 C. J. Davisson and L. H. Germer, at 
the Bell Telephone Laboratories, showed the reverse. They 
demonstrated that electrons, which had seemed to be separate 
particles, have many properties of waves. At about the same 
time at Cambridge, G. P. Thomson, brilliant son of J. J. Thom- 
son who discovered the electron, showed for the first time that 
electrons could be diffracted, another demonstration of their 
wave nature. It was from this pioneer work that the electronic- 
diffraction camera has developed as a practical tool. 

However, though this does not give an actual picture of the 
atoms, minute substances, even very large molecules or groups 
of atoms, can be reproduced, magnified, by electrons. Many in- 
dustrial laboratories are now equipped with the electron mi- 
croscope, using it for the examination of metals, of dust or 
smoke, of biological agents, and other substances. Where two 
thousand diameters represents the practical limit of the old- 
style microscope, using light, which was the best available un- 
til a few years ago, the electron microscope goes many times 
higher and permits the examination of details fifty times as fine. 

Early experimenters with cathode rays, before the electron 
had been heard of, found that the beam of rays could be bent, 
either by a magnet, or an electrostatic field around charged 
plates, much as a prism bends a beam of light rays. And just as 
a prism can be elaborated into a lens which will focus light rays 
to give a sharp image of a scene in front of a camera, so can 
electromagnetic, or electrostatic, fields be made that will focus 
a beam of electrons. 3 

The RCA instrument was the first to be placed on the Ameri- 
can market. The electrons, originating from the familiar hot 
filament, are speeded on their way with a 60,000-volt kick. This 
gives them enough speed to penetrate the specimen, which is 

8 In the electron microscope made by the Radio Corporation of America as the 
result of researches by Dr. V. K. Zworykin and his associates, the focusing is 
accomplished by electromagnets; other types use the electrostatic focusing. 


very thin perhaps about Moo ,000 inch. Of course, as with 
the diffraction camera, it is necessary to keep the apparatus ex- 
hausted of air. This imposes some limitation, though not a seri- 
ous one, on the nature of the specimens, since they must survive 
in a vacuum. Also, they must be at least partially transparent 
to electrons. 

The course of the electrons is exactly similar to that of light 
in the ordinary microscope. Coils of wire serve the same func- 
tion that lenses serve with light. A condenser focuses the 
beam on the specimen. The beam spreads, another electron 
lens picks it up and forms a somewhat enlarged image. Another 
lens picks up the electrons from this intermediate stage and fo- 
cuses them again to form the final image, with magnification as 
much as twenty thousand diameters. This can be seen on a 
fluorescent screen, which converts the electron image into one 
of light. Or the image can be formed on a fine-grain photo- 
graphic plate. From such a plate, when developed, prints 
greatly enlarged can be made, to bring the total magnification 
of the final micrograph to 100,000 times or more. 

In reporting recently to the American Chemical Society, Dr. 
Zworykin of RCA thus summarized the accomplishments of the 

To begin with, attention was naturally focused on bacteria, well- 
known and dreaded disease-causing micro-organisms. A "rogues' 
gallery" prepared with the electron microscope revealed a host of 
new detail which it will take years to interpret. As an early find, the 
blood-corpuscle-dissolving streptococcus haemolyticus was shown 
to be encased in a sturdy membrane which survived evacuation and 
electron bombardment. In the case of diphtheria organisms chemical 
reactions with tellurium salts could be observed with the individual 

The electron microscope proved to be especially well adapted for 
the study of the viruses, border-line organisms too small to be seen 
with the ordinary microscope, which are responsible for various plant 
and animal diseases. Some of these, like the tobacco mosaic and 
cucumber mosaic viruses, were found to be rod-shaped, others, as 
tomato bushy stunt and tobacco necrosis viruses, essentially spherical. 
It was possible to study in detail their mode of aggregation, as well 


as the action on them of chemicals and of the antibodies generated 
by animals to protect themselves against virus diseases. 

In the field of the higher animals, studies have been made of 
chromosome strands contained within reproducing cells. These are 
known to be the seat of the genes, or factors determining the in- 
heritable characteristics of the organism. Thus here the electron 
microscope may eventually aid in unravelling some of the secrets of 

Turning to applications in the inorganic world, the electron micro- 
scope is particularly effective in the study of finely divided matter, 
such as the carbon black as rubber preservative and as a constituent 
of various inks. Particle size and size distributions of carbon blacks 
of different origin are readily determined with the electron micro- 
scope. With pigments the shape of the individual particles and their 
consequent mode of aggregation and covering power are other im- 
portant factors which are revealed by the new instrument. 

These characteristics also govern the effectiveness of many insecti- 
cides and chemical absorbing agents. All of these have been subjects 
of study with the electron microscope. Even in the case of substances 
as homogeneous as modern plastics, this powerful instrument has 
been able to reveal minute structural detail invisible up to now. 

Finally the electron microscope has been put into service for the 
study of the surface of metals and other bulk materials. For this pur- 
pose a plastic replica of the order of Hoo>ooo i ncn m thickness is 
made of the surface. This is examined as any other transparent object, 
the degree of transparency being determined by the thickness of the 
replica at any point and, hence, by the contours of the original surface. 
In this manner metallurgists have followed out the important problem 
of the constitution of steel beyond the point where the metallographic 
light microscope could give information. 4 

But of the many accomplishments of the age of electrons, 
there is still another the most widespread of all. This is radio. 
Its story will be told in the next chapter. 

4 A simplified method of obtaining a plastic replica of a metal surface for 
examination with the electron microscope has been devised by Vincent J. 
Schaefer and David Harker, of the General Electric Research Laboratory. It 
is an adaptation of the former's work in preparing replicas of snowflakes and 
other short-lived forms. The illustration shows a specimen of carbon steel in 
a photomicrograph (taken with light) at 2,000 magnification, and an electron 
micrograph or a plastic replica at 28,000 magnification. 

XV. Radio Today and Tomorrow 

To many of us, radio began in the early twenties, when we 
sat with a pair of head-phones clamped to our ears, carefully 
tickling a galena crystal with a cat's whisker in the old crystal 
set, trying to pick up the feeble whispers of voice or music from 
one of the early broadcasting stations. But ten years before that 
a handful of amateurs, with noisy spark transmitters, were talk- 
ing back and forth to each other by "wireless"; and only ten 
years before that, in 1901, Guglielmo Marconi had sent his 
first signals between Cornwall, England, and St. John's, New- 

Thus radio actually began at the dawn of the twentieth cen- 
tury. Like other potential scientific advances, it had a great de- 
velopment during World War I; and that set the stage for the 
inauguration of broadcasting in the post-war period, beginning, 
as far as the United States was concerned, with KDKA, the 
Westinghouse station in Pittsburgh, which started transmission 
in 1920. In earlier days, the inability of the wireless to confine 
its message to a selected receiver had been thought a disad- 
vantage, but this very factor now made it possible for radio to 
play a role that was truly new, in permitting a speaker to be 
heard by millions, regardless of physical or artificial boundaries 
that might intervene. Even today we have hardly begun to 
realize the full implications of this medium. 

Although crude radiotelephony had been accomplished with 
the spark transmitter, the first regular broadcasters made use 
of the electronic tubes described in the preceding chapter. And 
soon after their beginning, and as commercially built receivers 
largely replaced the home-made sets of the early days, tubes 
were used for reception as well, and the crystal receiver be- 
came obsolete. 



Those first sets used largely the regenerative circuit which 
Edwin H. Armstrong had invented in 1912 while he was an 
electrical-engineering student at Columbia University. But they 
also acted as rebroadcasters of low power, and tended to pro- 
duce interference, in the form of squeals, in neighboring re- 
ceivers tuned to the same frequency. In later years they were 
extensively replaced by the superheterodyne circuit, also in- 
vented by Major Armstrong, who by that time had served in 
the U. S. Army Signal Corps. Now he is professor of electrical 
engineering at Columbia. 

If two whistles, of nearly but not quite the same pitch, are 
blown simultaneously near each other, the two sets of sound 
waves combine to produce beats. An analogous effect is seen 
when one looks through two parallel picket fences and sees a 
series of light and dark bands, which are considerably farther 
apart than the stakes in either fence. At one position, several 
openings in one fence line up with those in the other and there 
is a clear space. But a little farther on, the pickets in the distant 
fence are behind the openings in the nearer, and then there is 
a dark region. So it is with sound. First, the waves of one sound 
will combine with those of the other to reinforce them, as the 
two sets are in step. But because they are not the same length, 
they soon get out of step, and then one set cancels the other. 
This makes a set of waves farther apart that is, a sound of 
lower pitch than either one of the originals. 

A heterodyne circuit combines the vibrating current as re- 
ceived through the antenna with a current of a different fre- 
quency set up in the receiver, in such a way that beats are 
formed which bring the high frequency down into the "audio" 
range to within the limits of sensitivity of the human ear. But 
the superheterodyne produces beats which are still above the 
audio frequency range, so there is a second detector tube which 
brings it down the rest of the way. Such a circuit is used widely 
even though the manufacturers must be licensed under the 
Armstrong patents. 

In 1939 Major Armstrong contributed another invention, 


which may in the future prove just as popular as the super- 
heterodyne. This is frequency modulation, commonly called 
FM, which eliminates the old trouble of static, and also permits 
many stations to broadcast on the same frequency. 

Your present radio set is probably one which uses the older 
kind of transmission, that of AM, or amplitude modulation. 
About 50,000,000 of these, it is estimated, are now in use in the 
United States. In the AM transmitter special equipment, at the 
heart of which is an accurately ground crystal of quartz, keeps 
the station broadcasting on the frequency (or wavelength) to 
which it has been assigned by the Federal Communications 
Commission. That government organization constantly checks 
all transmitters, to be sure that they keep to their frequencies; 
and if they deviate, a reprimand or even a cancellation of their 
license will be the result. In contrast to this, the FM transmitter 
continually changes frequency, not haphazardly, but in a defi- 
nitely regulated manner; and this variation is what carries voice 
or music to the receiver. 

A good AM receiver tunes very closely. That is, when you 
tune with the dial, and not with pushbuttons, you have to set 
the indicator very accurately. If you move it a little one way or 
the other, the music varies both in intensity and in quality as 
you do so. Now, if the engineer in control of the broadcasting 
station were to vary the frequency of transmission while you are 
tuned to his station, the result would be similar. It is hardly 
difficult to imagine a station broadcasting a steady note, but 
varying its frequency in such a way that the receiver gets it 
first loud and then soft, and even reproducing speech and music 
in this way. 

Essentially, this is what happens with FM broadcasting, but 
entirely different circuits are required both in transmitter and 
in receiver to take effective advantage of frequency modulation. 

Suppose we have an AM station with a frequency of 810 kilo- 
cycles, that of WGY. This means that the "carrier wave" which 
is radiated from the station's antenna is vibrating 810,000 times 
every second. When your receiver is tuned to this station, it 


picks up this carrier, but the vibrations are much too rapid to 
be heard. It has to be modulated, and this is done at the trans- 
mitter. The circuit from the studio microphone regulates the 
height, or "amplitude," of the individual waves, though it does 
not affect the distance between one wave and the next. In the 
detector tube of the receiver, the carrier frequency is elim- 
inated, and the variations in amplitude are made into a vibrat- 
ing electrical current which, after being amplified some more 
and being fed into the loud speaker, will set up air waves that 
reproduce the original sounds. 

Lightning flashes are natural broadcasting stations, but, en- 
tirely disregarding the rules of the FCC, they do not keep to a 
single frequency. Instead they send out waves of many fre- 
quencies, so one of them will be the same as that of the station 
to which you are listening. Hence they join with the waves from 
the broadcaster, enter the set together, and give you a crash of 
static in the loud speaker. Electric razors, vacuum cleaners, and 
other kinds of electrical equipment behave in similar manner. 
As a result, with AM broadcasting there is no satisfactory way 
of eliminating static, since the waves that cause it are the same 
as those which you want, and one cannot be eliminated without 
the other. Only by getting close to a powerful station can the 
broadcast signal be made so strong that it actually overrides the 

With the FM station there is also a carrier wave. Since these 
transmitters have been assigned to the short waves, or high fre- 
quencies, the carrier is much more rapid than for the ordinary 
broadcasters. W57A, at Schenectady, for example, has a fre- 
quency of 45,700 kilocycles; that is, it vibrates 45,700,000 times 
every second. When the station is on the air, but while no signal 
is coming to the transmitter from the studio, the FM carrier 
wave is no different from that of an AM station under com- 
parable circumstances. 

When someone speaks into the studio microphone the effect 
on the carrier is very different; for now the amplitude of the 
waves remains the same but the distance between them, which 


determines the number that can occur in a second, changes. 
Frequency modulation stations are separated by 200 kilocycles; 
and this, with 50 kilocycles of clear space between adjacent 
channels, means that our station assigned to 57,700 kc will 
swing 75 kc either side of that mean, covering a range of 150 
kilocycles. Thus the FM receiver not only has to be able to time 
these short waves ( or high frequencies ) , but must also be able 
to tune in the signal over this range. In the AM stations, on the 
other hand, the separation between channels is only ten kilo- 
cycles. Consequently, a set must be designed to tune in a 
much narrower band otherwise it may pick up two stations at 

Now let us see what happens to static when it tries to inter- 
fere with FM broadcasting. Perhaps there is a flash of lightning, 
and the waves of the static join with the broadcast wave, pro- 
ducing a variation in amplitude as well as in frequency. This is 
picked up by the aerial, and the static actually gets into the 
receiver. But in it there is a "limiting circuit." This, in effect, 
chops off the tops and bottoms of the waves by the use of 
electron tubes, making the amplitude constant again before the 
detector tube gets the incoming signal, so it has no knowledge 
of the static. The detector circuit now converts the changes in 
frequency into changes in amplitude; and from there on to the 
loud speaker, the process is just about the same as in older 

Because AM receivers, even if they could tune the short 
waves broadly enough, lack the limiting circuit and the con- 
verter to change frequency variations over into changes of 
amplitude, they will not tune in frequency modulation. But 
"translators" are available commercially. These are FM re- 
ceivers without the final audio amplification and loud speaker 
of a complete set. When fed by the proper antenna, and plugged 
into the AM receiver like a phonograph attachment, thev make 
use of the same amplifiers and loud speaker. Also, combination 
sets have been made with translator built in, which can be 
used both for FM and AM reception. 



Several factors have been responsible for assigning the FM 
broadcasters to the short waves, about twenty feet in length, 
instead of to the thousand-foot waves of the AM stations. For 
one thing, this region was not so crowded; but it also has other 
advantages, for it is easier to design frequency-modulation 
circuits for these frequencies than for those in the usual broad- 
cast band. And further, the waves being so small, it is simpler 
to provide antenna systems which are more efficient, or which 
have better directional characteristics that is, in picking up 
signals from one preferred point of the compass than with the 
longer waves. 

An engineer, I. R. Weir, determined, both by calculations 
and actual tests, that the area^pf good broadcast reception with 
FM is about 33 times Create* -w&^with amplitude modulation. 
He has compared two AM transmitters fifteen miles apart on 
level ground with two FM units similarly separated. If the two 
AM stations operate simultaneously on one kilowatt of power, 
reception is satisfactory in a circle of a mile-and-a-half radius 
from each. Outside these circles, the stations interfere with each 
other. But now consider the action of the FM stations under the 
same conditions. Then the area around each in which the 
reception is satisfactory, with no interference from the other, is 
jSSjdmes, asgreat as with amplitude modulation. 

Weiraetermined what happened with increased power. Rais- 
ing one of the AM stations to ten kilowatts increased its area of 
clear reception three-fold, and reduced that of the one-kilowatt 
station to a third of what it had been. With FM, the increase 
around the more powerful station was also about three, and / 
the decrease around the weaker station was to a quarter; but 
this still left it with an area 23 times as great as that of one of 
the AM stations, even with equal powers. With FM there is 
practically no place where two stations are heard together. If 
you were to travel in an automobile, equipped with an FM 
receiver, from one transmitter to another, there would be a 
rather sudden change. Up to the point where they became 
nearly equal in intensity, one would be heard plainly, to the 

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exclusion of the other. Then soon afterwards you would enter 
the service area of the new station; that would be heard, and 
not the one you left behind. A similar experiment with AM 
would show a large area where both stations were heard to- 
gether, for the next one would build up as the first one 

There is another reason for the better quality of FM broad- 
casting, and that is the greater width of the roadway on which 
its signals are carried from transmitter to receiver. The deepest 
note which the ordinary human ear can detect vibrates about 
16 times a second. This would be fourth C below middle C on 
the piano. No piano goes down that far, but large organ pipes 
do. At the other extreme are the highest pitched notes to which 
the ear is sensitive, which vibrate about 16,000 times a second. 
Typical of this is the squeak of a door, or the chirp of an insect. 
No ordinary musical instruments get this high; yet for every 
note of such an instrument there is not only the fundamental 
tone, but also a series of overtones, some of which approach this 
figure. These are made as the note is played, and are all higher 
pitched than the fundamental. With them, in a concert hall, the 
music sounds rich and natural; with the overtones eliminated, 
you still may recognize melodies, but the color of the music is 

With more than 880 radio stations in the United States 
crowded into the 105 separate and available channels of 
frequency which lie between 550 and 1600 kilocycles, it has been 
necessary to limit each channel to a ten-kilocycle width. Since 
the stations cannot go exactly to the edge of each channel and 
stop there, they actually keep within a range still narrower 
not more that 5000 cycles across and this makes it impossible 
to transmit, by conventional radio, the very deep and the very 
high notes; a great loss in the case of a symphony concert. With 
the 20-kc channels assigned to FM, the transmitter has an 
effective range of 15,000 cycles, which covers practically all the 
range of sounds from the deepest to the highest. The deepest 
notes of the'bfeoe^or of the contrabass, and the shrill tinkle of the 


triangle or the high overtones of crashing cymbals, all reach the 
listener with frequency modulation. 

Of course, at no point in the radio circuit must there be any 
limitation of the frequencies. Otherwise they are lost, and there 
is no advantage in having the transmitter able to broadcast them 
if they do not reach the FM-broadcasting station. Since the wire 
networks linking the nation's broadcasters were planned for AM 
and are mainly used with it, there was no point in making them 
able to carry a greater frequency range than the stations could 
broadcast. Consequently, an FM station that is connected to the 
source of a broadcast by the customary telephone program 
circuit never gets the full frequency range, though its trans- 
mission still retains the advantage of freedom from static. No 
doubt as FM broadcasting becomes more common, special 
program lines of high range will be provided for their use. 

Frequency modulation's freedom from interference makes it 
of value in other radio fields. It is used for police radio com- 
munication, for carrying programs to schools, for public utilities 
to give instructions to service trucks, for communication be- 
tween airplanes and the ground. United States quarantine tugs 
in Boston Harbor and the Quarantine Administrative Head- 
quarters in the Boston Customs House can thus keep in touch, 
despite interference from static caused by compressors and 
other machinery in near-by plants that used to be a frequent 
source of interference. 

But it will be its entertainment value, in the home, that is 
going to make FM radio familiar to most of us. We shall be 
able to hear speakers, orchestras, singers, outdoor events, with 
greater realism than at present. Frequency-modulation radio 
will go along with television; in fact, the FCC has ordered that 
all sound accompanying television transmission be sent by this 


And what of television itself? It made its debut in the late 
1920s. After pioneer work by Dr. E. F. W. Alexanderson of 


the General Electric Company, and by a Washington inventor, 
C. Francis Jenkins, who was able to send moving silhouettes by 
radio, the first large-scale demonstration came in April, 1927. 
Mr. Herbert Hoover, then President Coolidge's Secretary of 
Commerce, was the most eminent person of a little group, of 
which the writer was a member, which gathered one afternoon 
in a transformed funeral parlor. It was no death, but a birth, that 
we witnessed the birth of television. Different members of the 
party sat in front of the transmitter; a spot of light flashed over 
our faces many times a second. Each time the spot would fall 
on a light-colored area, illumination would be reflected to a 
bank of photocells, and the varying current from these would 
record the lights and shades of the subject. Amplified, carried 
over long-distance telephone lines to the Bell Telephone Lab- 
oratories in New York City, these currents controlled the light 
of a luminous plate in a neon tube. Revolving in front of the 
plate was a "scanning disc," with a series of holes around the 
edge which, at each instant, exposed a part of the viewing plate 
that corresponded to the position of the light spot at the same 
time on the subject in Washington. The viewers saw a recog- 
nizable portrait, in the pink color of glowing neon, of the 
subject two hundred miles away, for, since the plate was com- 
pletely swept over many times per second, the same persistence 
of vision that makes motion pictures possible fused all the spots 
into a complete picture, just as the dots of a half-tone repro- 
duction of a photograph are fused together. 

About the same time, John L. Baird was making his early 
experiments in England, with results that were even cruder. He 
did not then use the moving spot, but flooded his subject with 
light and picked up parts of the image as formed by a lens. This 
required uncomfortably great quantities of light, so he often 
used invisible ultraviolet rays and as the picture became 
visible he had "noctovision," or vision at night. 

The idea of television, curiously enough, dates back to 1884, 
for it was in that year that a German inventor named Nipkow 
was granted a patent on apparatus which, in its essentials, was 


practically the same as its first successful modern counterpart, a 
selenium cell, made of an element which changes its electrical 
conductivity with the amount of light falling upon it, was the 
retina of his electric eye, and a very unsatisfactory one, not 
nearly so good as the modern photocell. Further, Nipkow lacked 
electronic tubes for amplification, so it is not surprising that his 
method never operated. In 1910 another inventor, A. Ekstrom, 
was granted a Swedish patent for a system like that of the Bell 
Laboratories, in which the spot of light, rather than the image, 
was moved. He too lacked the modern methods of amplification, 
and there is no record of his having succeeded. However, these 
preliminary ideas in no way detract from the credit due to the 
modern experimenters, who have achieved the old dream of 
"seeing at a distance." 

In 1927, Dr. Alexanderson and his associates also achieved 
television, and in 1929 they reproduced their images on the 
fluorescent screen of a cathode-iay tube by a stream of elec- 
trons. This was the forerunner of modern electronic picture 
tubes. A little later Dr. V. K. Zworykin, Russian-born television 
expert of the Radio Corporation of America, developed an all- 
electronic television system, and this made the scanning disc 
obsolete, both for transmitting and receiving. 

The eye of modern television is the camera which, like a 
photographic camera, has a lens to form an image on a plate. 
But the plate in this instance is a sheet of metal, in an evacuated 
glass tube, covered with myriads of tiny photoelectric cells. 
Each cell, as it receives light from the image formed upon the 
plate, builds up an electrical charge in proportion to the intens- 
ity of light falling on it. Thus, over a bright part of the picture, 
the minute cells accumulate relatively large charges, while 
those in the dark areas have practically none. 

In a neck extending from the camera tube is an electron gun, 
which shoots a very thin beam of electrons toward the photo- 
cell mosaic. Outside the neck are coils of wire through which 
pass alternating currents, and these cause the electron beam to 
sweep over the plate at a speed of about three miles per second. 


From the lower right it moves horizontally across; then starts 
over again just above the place where it started first, and makes 
another trip. After 525 such horizontal paths have been traced 
in a thirtieth of a second the whole area has been covered, 
and the beam goes back to the lower right to begin over again. 

Every time one of the photocell elements is touched by the 
electron beam it releases its charge which, becoming an elec- 
trical current, is sent over cables to the amplifier and the trans- 
mitter. The intensity of this current at any instant is a measure 
of the amount of light falling on the part of the camera-tube 
plate which is then being scanned by the electrons. Next, this 
current is either sent over wire lines to the receiver or, in the 
case of radio television, modulates the carrier of the transmitter, 
usually by amplitude though this could also be done by fre- 

Since each television picture is made up of about 275,000 
separate units, corresponding to the dots of a half-tone repro- 
duction, and since thirty of these are formed every second, it 
means that more than 8,000,000 individual impulses should be 
sent in a second to realize all the theoretical possibilities. This 
would mean a band far wider than required for the best FM 
sound transmission. In the whole broadcast range (from 600 to 
1500 kc) which covers only 900,000 cycles, there is not enough 
room for one television station of such channel width. 1 

When the signal reaches the television receiver, and the 
sight, or "video," component is sorted out from the sound or 
"audio" part, the electrical impulses are amplified and sent into 
the picture tube. In this a beam of electrons scans the viewing 
end in exact step with the electron beam in the camera tube, 
and falls on an inner coating of a fluorescent material, which 
glows where the electrons strike. The brilliance of the glow 

1 Actually, television channels assigned by the FCC are in the ultra-high fre- 
quency bands, where there is considerably more room, and the channels cover 
only 6,000,000 cycles (or six megacycles). Of this, part has to be used for the 
sound accompaniment, and some room has to be left between sound and sight, 
which leaves but 4.5 megacycles for the visual broadcast. For station WRGB, in 
Schenectady, for example, the center of the channel is 67.25 me, or 4.6 meters. 


varies with the intensity of the electron beam which, in turn, 
changes with the strength of the incoming signal. As this is con- 
trolled by the brightness of the corresponding point on the 
camera tube at the same instant, the picture is made up of light 
and dark areas which correspond to the original scene. Persist- 
ence of vision, just as it did with the old Nipkow scanning 
method, combines all the points into a continuous picture. To 
aid this, the glowing material that the electrons activate is often 
made slightly phosphorescent as well as fluorescent. That is, it 
continues to glow even after the exciting rays are removed. If 
this glow continues too long, however, moving objects appear 
with cometlike tails following them; but when the phosphores- 
cence is limited to a thirtieth of a second, it merely bridges the 
interval and is gone by the next time the scanning electron 
beam comes along. 

Early television experimenters found synchronization a prob- 
lem; that is, the transmitting and receiving scanning discs had 
to move in exact correspondence. But with the electronic sys- 
tem, this is achieved by a separate electrical impulse, which 
periodically co-ordinates the electron beam in the camera with 
that in the picture tube. At the end of each line, and at the end 
of each separate picture, the beams are brought back to the 
starting point together, ready for another trip. 

In the 1927 television days, one experimenter said to the 
author: "If we can tell a face from a fish, we think we're doing 
pretty well!" 

Modern television, which is now being broadcast and re- 
ceived by a small number of sets from a handful of transmitters 
in a few cities, is a vast improvement, and is approximately 
equal in quality to good home movies. In 1941 the U. S. Gov- 
ernment finally authorized commercial operation of television 
stations, but the advent of the war, and the cessation of the 
building of civilian radio receivers, halted the development 
which otherwise would then have come. However, experimen- 
tation did not entirely cease; some continued with war applica- 
tions as the goal, so that after the peace television should be 


ready for a rapid enlargement, which will undoubtedly far 
surpass that of sound broadcasting in the post-World War I 

The ordinary television receiver displays its picture on a 
screen about as large as a double-page spread of this book. This 
size is satisfactory for a small group in the home, but would not 
do for an audience in a hall. At the time of the 1927 Bell demon- 
stration from Washington to New York, a large viewing device 
was used, consisting of forty-eight parallel and interconnected 
glass tubes, filled with neon, inside which were a series of elec- 
trodes. In place of the scanning disc was a commutator a 
motor-driven switch which successively connected all these 
electrodes; and glowing spots of proper intensity appeared 
around each, thus making a large picture. 

A little later Dr. Alexanderson showed large-screen television 
in another way. A neon "crater" lamp was used. This gives a 
small bright spot of light from glowing neon gas; and it was 
made to vary by the incoming signal. A scanning disc, with a 
spiral row of lenses instead of mere holes, focused this spot on 
a screen and made a series of lines of light across it, which 
formed the picture. Still another scheme, to get more light, re- 
placed the neon lamp with an arc light; and to regulate the 
illumination this used a "Kerr cell," which is a sort of valve 
that permits a varying electric current to control the intensity 
of light shining through it. Again the lens disc was spun to pro- 
duce the screen picture. 

In line with the all-electronic tendency of modern television, 
the lens disc has gone the same road as the scanning disc. By 
using a picture tube of high intensity, the picture may be made 
brilliant enough to project in the same way as the illuminated 
slide of a stereopticon by putting a lens in front of it and 
forming an enlarged image of the picture on a screen. By op- 
erating the picture tube at a very high voltage the picture can 
be made quite brilliant; but for a full-sized motion-picture thea- 
ter screen, the same amount of light has to be considerably 
diluted as it is spread over the larger area. This means that 


waste of light in the projector must be reduced to a minimum, 
and the very "fastest" lenses must be employed. 

Here is exactly the same problem involved in taking photo- 
graphs in a dim light. Not only must the film be extremely 
sensitive, but the lens must have a large "focal ratio," which is 
the number of times the diameter of the lens goes into its dis- 
tance from the film or, in the television projector, its distance 
from the picture tube. Lenses in which this ratio has a value of 
F 2 or even F 1.5 have been used, their effective speed being 
further increased by the non-reflecting coatings already de- 
scribed. But in the most recent demonstration, which was given 
by the National Broadcasting Company in a New York theater, 
a new tool of the astronomer was employed. 

In taking photographs of faint stars, the astronomer also re- 
quires great speed, combined with an instrument that will cover 
a relatively large area of the sky. About 1930 a young German 
astronomer of Hamburg, Bernard Schmidt, invented a type of 
camera which is now very popular and which bears his name. 
The ordinary telescope has a convex lens which forms the 
image, like a camera, and this is called a refractor. Other types 
of telescope, called reflectors, are also widely used, with a con- 
cave mirror to focus the light rays. The curve of such a mirror 
is not an arc of a circle, as that would not focus all the rays to- 
gether, but is a parabola. The Schmidt camera, however, does 
make use of a spherical mirror, in which lines across the surface 
are circular arcs. To focus all the rays in the same place, they 
pass through a correcting plate before they strike the mirror. 
This is a complicated lens which is partly concave and partly 
convex. After the light rays pass through it, they hit the mir- 
ror in such a way that all are focused sharply on the curved 
film, about halfway between the plate and the mirror, which it 

It is a fundamental rule of optics that a beam of light does not 
care which way it goes; if the beam will pass through a lens 
system in one direction, it will go equally well if its route is re* 
versed. So, with the Schmidt camera, the curved film can be 


replaced with a curved source of light, the rays will be reflected 
from the spherical mirror, then will pass through the correct- 
ing plate; and they can be focused to form a large image on a 
screen. This is what the RCA television projector does. The 
curved surface of the picture tube takes the place of the film 
and, since the Schmidt camera can be made with a speed of 
F 1, this utilizes more of the light than any other projector. 
At the New York demonstration, the projector was sixty feet 
away from the screen, yet the picture, fifteen feet high and 
twenty feet wide, was almost as bright as the ordinary motion 
picture. Perhaps, in the future, with such a device, theaters will 
regularly show programs of events happening in other parts of 
the world, at the same time that they are occurring. 

Even greater realism would be obtained if the television 
images, whether in home or theater, were in natural color; and 
this, too, has been achieved. The Bell Laboratories scientists 
did it in 1929, about the same time that Baird was doing it in 
England. To reproduce all the colors of a scene, three separate 
pictures are required, each showing one of the fundamental 
colors, red, green and blue. Color prints in books and magazines 
are made by superimposing three separate color impressions. 
In the 1929 television methods, three complete transmission 
systems were used. Properly colored filters picked out the colors 
desired. One system transmitted the reds, another the greens 
and the third the blues of the original. At the receiver, each 
picture was reproduced in the corresponding colors. With an 
arrangement of mirrors which partly reflected and partly trans- 
mitted light from the other side, the three were recombined, 
and the looker saw them fused into one picture again. 

More recent experiments by Dr. Alexanderson in Schenec- 
tady, and by Dr. Peter C. Goldmark, chief television engineer 
of the Columbia Broadcasting System, make use fundamentally 
of the principles of the first commercially successful color-movie 
system. This was the "Kinemacolor" process which, in 1910, re- 
vealed to the world the glorious colors of the pageantry at the 
coronation of King George V, and also, the following year, 


those of the Indian Durbar at Delhi, when he was crowned 

The Kinemacolor camera ran the film at a speed of thirty- 
two frames per second, twice that of the current standard for 
black and white. (Twenty-four frames per second became 
standard with the coming of sound films.) A revolving color 
filter, half red, half green, took alternate exposures in each 
color. In the projector revolved a similar disc, giving each frame 
the same color as it was taken with. Once more persistence of 
vision operated and the eye saw the pictures combined. 

With two instead of three colors, it was not possible to 
reproduce all the tints of the original. Also, there was often 
trouble with "color fringes." That is, if a subject moved an arm, 
it would be in one place as the green frame was taken, but 
would have moved to a different position for the red. On the 
screen, instead of a sharply defined arm, would appear a blur 
of separate red and green images. 

Both of these difficulties are eliminated in the new color- 
television method. The revolving screen has three colors, in- 
stead of two. And to eliminate fringes, Dr. Goldmark revolves 
his filter 250 per cent faster than it did in the Kinemacolor 
camera. With that system a complete picture, with both colors, 
took VIQ second. In the Goldmark camera the three compo- 
nents are all completed in ^o second, so there is less chance 
for the color blurs to appear. 

This method really involves no fundamental change from or- 
dinary television, since all three colors are sent over a single 
channel. Essentially, any modern television system can be con- 
verted to color merely by putting color discs over the cameras 
and the receivers, and providing the means for moving them in 
step. This is not difficult, since exact synchronization must be 
provided in any event for the beam of electrons in the picture 
tube. And a receiver that is not equipped for color can still 
show the colored transmission as black and white. Perhaps it 
is not too much to hope that, by the time television does achieve 
widespread popularity, it will all be in color. 


The widespread popularity of sound broadcasting came with 
the development of the networks, enabling the great expense of 
producing an elaborate program to be spread over many sta- 
tions. With sponsored programs the advertiser is assured of an 
audience sufficiently large to warrant his heavy costs. Television 
is even more expensive than sound, so it seems certain that some 
sort of television network will be essential if it is to develop. 

Just as the ordinary ten-kilocycle channel for sound broad- 
casting will not transmit nearly enough range for television, 
neither will the telephone lines connecting broadcasting sta- 
tions transmit the millions of separate impulses needed each 
second. Special equalizers and amplifiers do make it possible 
for good telephone circuits to carry about 3,000,000 cycles per 
second, and for television this may serve over short distances 
temporarily. But for city-to-city connections it has to be better 
than this; and the coaxial cable is one answer. 

Long-distance telephony is usually carried from city to city 
by what might be thought of as radio over wires. That is, the 
voice currents, which are vibrating a few thousand times a sec- 
ond, and in the range to which the ear is sensitive, are stepped 
up to vibrate at frequencies similar to those used in radio trans- 
mission. The original vibrations, from zero to 4000 cycles per 
second, may be changed into a range from 60,000 to 64,000 
cycles per second. Another conversation, going on at the same 
time, may be stepped up to the 64,000-68,000 range, another 
to 68,000-72,000. Long-distance trunk lines are capable of a 
range of 48,000 cycles, or from 60,000 to 108,000, so twelve 
separate conversations, each in its 4000 cycle band, can all be 
sent at the same time. Along the way amplifiers, or repeaters, 
give these currents occasional boosts. Thus, not a great deal of 
power is needed at the start, since power is added when needed 
along the line. 

At the end are separate receivers for each conversation, and 
each is tuned to a particular 4000-cycle band, so they are sorted 


out again. Then they are stepped down to vibrate at the rate 
to which the ear responds, and the other party hears the voice 
from afar faithfully reproduced, in spite of all that has been 
done to it en route. 

Under present conditions a range of 48,000 cycles, carrying 
twelve conversations, represents about the limit that can be 
transmitted over the ordinary wires. To carry more it is neces- 
sary to go to still higher frequencies than 108,000, and then in- 
terference increases. For instance, there is more crosstalk; that 
is, one line picks up messages from a near-by line and mixes 
them in. 

To overcome these difficulties, the Bell engineers turned to a 
type of conductor that had been studied years before and even 
used for some purposes, though their application was new. As 
first installed in 1935 between New York and Philadelphia this 
"coaxial cable/' as it is called, consists of a copper tube about as 
big as a lead pencil. Running through its center, held in place 
by a disc insulator every few inches, is a copper wire. The wire 
and the tube form the two parts of the circuit, and the air be- 
tween them is a much better insulator than any ordinary in- 
sulating material that might be used. At the same time, the 
copper tube acts as a shield to bar outside interference. 

Actually, on account of the "skin effect," although the tube 
has a solid copper wall, the undesired interfering currents travel 
along the outer surface, to the ground, while the voice currents 
are concentrated on its inner surface. The higher the frequency, 
the more pronounced is this effect. 

Thus, the coaxial cable can carry a range of a million cycles, 
or 240 messages simultaneously, each with its 4000-cycle band, 
and with a little space in between for clearance. Or, instead, the 
whole million cycles may be used for television. This was done 
in June, 1940, when the first intercity television broadcast was 
made. Scenes from the Republican National Convention in 
Philadelphia were sent out from the Empire State Building 
transmitter. It is for telephony, however, that the coaxial cable 
has been most used up to now. So successful did it prove that 


in 1940 another was installed, between Minneapolis and Ste- 
vens Point, Wis. Actually such a cable is double; in a single larger 
housing there are two coaxial conductors, one for each di- 

Coaxial cables are expensive $20,000,000 has been esti- 
mated to be the cost of one crossing the continent. It hardly 
seems likely, therefore, that our present elaborate network of 
program lines for broadcasting will be duplicated for television. 
What is more probable is that we shall have radio links, used, 
perhaps, as branches from a few coaxial trunk lines. 

The first radio link was put into service on January 12, 1940, 
when NBC television programs were first received from New 
York City, 129 miles away, by a special relay station in the 
Helderberg Mountains near Albany. These are passed on a 
mile and a half, again by radio, to the General Electric tele- 
vision station WRGB, situated on a cliff overlooking the three 
cities of Albany, Troy and Schenectady. In all of these the pro- 
grams can be received clearly, though the original transmission 
from the New York station on the Empire State Building can- 
not ordinarily be observed. 2 The reason for this is that the 
short waves used for television travel in straight lines; they are 
not reflected back to the ground, as are the long broadcast 
waves, by the strata in the high atmosphere making up the 
Kennelly-Heaviside layer. Thus they are stopped by the inter- 
vening curve of the earth, since they do not jump around it. 

The Radio Corporation of America makes use of radio trans- 
mission to carry television from points on Long Island to the 
New York City transmitter. In one demonstration, for example, 
views from Camp Upton, sixty-eight miles away, were relayed 
in three jumps. The NBC mobile transmitter, in two large 
trucks, sent the signals seventeen miles from the camp to Haup- 
pauge, where they were automatically received and passed to 
Bellmore. This station sent them twenty-eight miles more to a 
receiver on the sixty-second floor of the RCA Building in New 

2 A radio link is also used to relay the programs from the WRGB studio in 
Schenectady to the same transmitter. 


York City, whence wire lines carried them to the transmitter. 
This was done with very low power only five watts in the 
intermediate relay transmitters, a feat possible largely because 
of the highly directional horn antennas used in the receivers. 
These point directly to the transmitter, and taper from their 
4x6 foot openings, along their eight-foot length, to an apex a 
foot and a half square, where a small dipole antenna is located. 

Though it is in broadcasting that most of us have contact 
with the wonders of radio, there are many other uses that have 
perhaps greater importance. Radio today makes possible the 
great network of aerial transport, warning the pilots of adverse 
weather conditions, and permitting them to keep their ground 
stations informed of their progress. Applied to police use, it is 
making crime more and more difficult. Automatic transmitters, 
carried miles aloft by small balloons, report weather condi- 
tions high in the atmosphere, permit more accurate forecasts 
of future weather. And all the time the use of radio for which 
it first gained fame in calling aid to a sinking ship has con- 
tinued, especially when hostile submarines patrol our coast. 

For the purposes both of business and diplomacy men can 
talk to one another though separated by oceans. Before the 
beginning of the Second World War, engineers of the Bell 
System had very nearly achieved their aim of making it pos- 
sible for any person in the world with a telephone to talk to 
any other person similarly equipped. Such conversations would 
not be of much value, however, if a business rival, or an enemy, 
could listen to secrets and use them to his own advantage, so 
numerous "scrambling" methods have been devised, making the 
signal received by an ordinary set like so much gibberish. 
Yet the authorized receiver can unscramble it and make the 
speech perfectly intelligible again. One of these methods is to 
change the places of high- and low-pitched sound, so that "tele- 
phone company," for example, sounds like "playofine crinko- 


nope." Other methods are even more complicated; and the par- 
ticular combination used can be changed frequently, so that 
even an enemy who knew the system and had the necessary ap- 
paratus would still lack the essential key to interpretation. 

Within a few years, perhaps, telephone conversations across 
the Atlantic will take place by cable as well as radio, and then 
such juggling of the messages to gain secrecy will be unneces- 
sary. The ordinary telegraph cable, like those which have con- 
nected America and Europe since 1865, does not respond 
quickly enough to transmit the rapidly changing currents re- 
quired by telephony. The reason for this is that the cable is 
really a large condenser, which "stores" electricity. Hence it is 
necessary to charge it before a signal appears at the other end, 
and this takes an appreciable time. 

In 1924 Dr. Oliver E. Buckley, now director of the Bell Tele- 
phone Laboratories, devised a cable with a sheath containing 
a new alloy called "permalloy." Although this speeded up the 
cable five or six times, it was still too slow for telephony, at 
least over a distance as great as that across the Atlantic. Even 
before this, in 1921, a telephone cable 105 nautical miles in 
length had been laid between Key West and Havana. 

Further experiments showed that the use of another alloy, 
called "perminvar," would make possible the construction of a 
long-distance telephone cable, capable of spanning the 1800 
miles from Newfoundland to Ireland; and in 1929 such a cable 
was projected. Though regular transatlantic radio-telephony 
had then been inaugurated, it was unreliable, and the expendi- 
ture of $15,000,000, which the cable would have cost, was con- 
sidered warranted to assure a continual connection. 

In his 1942 Kelvin Lecture given before the Institution of 
Electrical Engineers in London, Dr. Buckley explained that the 
business depression caused a temporary postponement of the 
project. Then, as the reliability of radio-telephony was greatly 
improved, it was decided that such a cable, carrying only a 
single conversation, was no longer justified. On the other hand, 
if a cable capable of carrying simultaneously a number of con- 


versations were feasible, the economic case might be different. 

Though it still presents many problems, it now seems likely 
that such a cable can be made, and in his lecture Dr. Buckley 
outlined its features. As in land lines, such a cable would have 
to have repeater stations at regular intervals to give an extra 
push to the ever-weakening currents and send them on their 
way. But putting repeater stations on the bottom of the ocean 
is rather a different matter from placing them along a regularly 
patrolled land line. Since the lifting of a cable for repairs is a 
complex process, involving the grappling for it from a specially 
equipped ship, the parts of the cable repeater station must re- 
quire little or no servicing. The Bell engineers set twenty years 
as the minimum time over which the station should work with- 
out attention. 

Principally, Dr. Buckley pointed out, this is a matter of mak- 
ing a rugged and long-lived electronic tube. So a tube has been 
developed which already has given continual service for more 
than five years without deterioration. It seems likely that it will 
run for at least twenty years, but that remains to be proved. 
Such tubes are made for this special purpose, and they are 
hardly suitable for home radio sets! Long life is obtained only 
with the sacrifice of some other desirable qualities. 

Using these tubes, the men at the Bell Laboratories have 
devised a repeater which is contained in a section of the cable 
itself. About two inches in diameter, and seven feet long, 47 
of them, at 42-mile intervals, would be required in a cable con- 
necting Newfoundland and Great Britain. The tubes need 
power for their operation, and it is planned to supply this over 
the cable itself from a direct-current supply. 

The time has not yet come to build such a cable, and many 
important problems remain to be solved before it is really prac- 
ticable. These solutions will come through the construction of 
trial sections, and their testing under a variety of conditions. 

As foreseen by Dr. Buckley, however, there would be a pair 
of cables, one for east-west transmission, the other for west- 
east, since the repeater is a one-way device. In this manner, he 


said, a band of 48,000 cycles could be transmitted. This would 
carry twelve simultaneous conversations with quality equal to 
the best present land telephone practice. If the quality be sacri- 
ficed slightly, though not enough to make the speech hard to 
understand, it would carry twice this many. 

It is estimated that the cost of such a cable would be no 
higher than for short-wave radio systems to carry the same 
number of circuits. And there is also the better quality of cable- 
transmitted speech, its privacy and greater reliability which 
might even justify higher cost. 

"When once the engineers are ready to give reasonable as- 
surance of the cable," said Dr. Buckley, "I believe that it will 
not have to wait complete economic justification, because of 
the tremendous importance which it would have in insuring 
privacy and continuity of transatlantic telephone service." In 
fact, he added, "it is possible that once the cable were in service 
radio would be looked upon as a supplement to it." 

XVI. Light and Light Sources 

Man's earliest illumination was the sun; and it is perfectly 
correct to say that even in this age that celestial body, 92,900,- 
000 miles away, is our only source of light. One form of energy 
is light; all energy comes ultimately from the sun; and much of 
man's ingenuity throughout past ages has been expended in 
bringing in the sun's brilliance, in keeping it to illuminate his 
dark hours. Of course, the cave men never realized that the 
wooden faggots they burned were actually giving off energy 
that the living tree had acquired from the solar radiation it had 
absorbed through its leaves. 

It is fortunate that the eye has such adaptability that it can 
stand a range of brightness from the faintest visible light which 
can be seen to one that is actually uncomfortably brilliant: of 
about one to 1,000,000,000,000. Since we cannot control the 
brightness of the sun, artificial illumination, without such 
adaptability, would have to be many times brighter. 

The most familiar unit of light intensity is the candlepower, 
which is approximately the brightness of an ordinary candle. 
But in technical work the lumen is more commonly used. This 
measures not the brightness but the quantity of light energy 
that flows out from a source. A lamp of one candlepower, from 
which it is given off uniformly in every direction, yields a little 
more than 12.5 lumens. 

The eye is not equally sensitive to all colors. Light of yellow- 
green color affects it most; and to equal the apparent bright- 
ness of a particular yellow-green source five times as much power 
in orange-red light would be needed, or sixty times the power 
in blue-violet. What we call white light is simply the particular 
combination of the colors of the spectrum given off by sunlight, 
plus some light of a more bluish color which the sky scatters. 



When, in an artificial light, we demand that the same propor- 
tions be observed, we are asking that it contain some of the 
colors we can see rather poorly. 

If we have a lamp emitting only the yellow-green light that 
we see best, we can get the most light for our money. Such a 
lamp, if it were perfect, would yield 621 lumens for every watt 
of electricity put into it. As the yellow light of the sodium lamps 
used for highway illumination is approximately of this color, 
they are quite efficient compared to other sources they give 
about 50-55 lumens per watt of power, or about a twelfth of 
what might be done. Since most of us do not find it pleasant 
to work or play under such a color, as we want things at night 
to have something like their normal hues, we ask for "white" 
or an approximation and this cuts the maximum theoretical ef- 
ficiency of a lamp to about 225 lumens per watt. There is still 
considerable room for improvement, for the most efficient lamp 
yet developed to give white light (the high-intensity mercury 
lamp, with water cooling ) yields only 65 lumens for every watt 
of power. However, our engineers need not feel too badly about 
this, since the sun, it has been estimated, gives only about one 
hundred lumens per watt. 

The sun, like the incandescent lamps which give off light 
from a heated filament, radiates as well a considerable amount 
of the invisible ultraviolet and infrared rays, which are of no 
use directly for illumination. However, continual research has 
made the modern Mazda lamp a far more efficient device for 
converting electricity into light than was its prototype, Edison's 
first crude lamp that started to shine at Menlo Park on October 
21, 1879. With a filament of carbon, these early lamps con- 
sumed somewhat less than 100 watts, and gave about 1.7 lu- 
mens per watt when they were new. But carbon evaporated 
from the filament and settled on the bulb, so that by the time 
they were about to burn out they would average scarcely better 
than one lumen per watt. 

By 1900 the incandescent lamp was of age; Edison and others 
had worked to double its efficiency and make the average lamp 


burn for six hundred hours. In that year Edison is reported to 
have remarked that it was then so perfected that he thought it 
unlikely that it would ever be materially improved. 

Similar remarks have often been made. For example, it was 
only a few years after this, shortly before the Wright brothers 
made their first flight at Kitty Hawk, that a distinguished 
American scientist demonstrated, to his own satisfaction at 
least, that it was quite impossible for man ever to make a 
heavier-than-air machine which could get off the ground. Such 
a statement is very often the signal for someone to prove it 
wrong, and this was done in regard to Edison's pessimistic view. 

It was in that same year, 1900, that the General Electric Re- 
search Laboratory was established. Since incandescent lighting 
has from the start been the backbone of the electrical industry, 
this was one of the problems that Dr. Willis R. Whitney, first 
director of the Laboratory, began to work upon. The result was 
the "Gem" lamp of 1905, produced by subjecting the specially 
treated filaments to high temperature before they were placed 
in the lamp, and thus giving them a "metallized" finish. This 
reduced the amount of blackening of the bulb in use, and 
these lamps, with the same efficiency as the old ones, burned 
nearly five times as long, or else, with the same life, were 25 
per cent more efficient. 

The next great improvement was to eliminate the carbon 
filament entirely. In 1906 lamps with a metal filament, made of 
tantalum, were introduced in the United States, but these were 
not satisfactory, as their life was short, especially with the al- 
ternating current then coming into wide use. A filament of 
tungsten was much better, and gave a result 80 per cent more 
efficient than the one in the Gem lamp. 

Tungsten lamps, made in Europe, were brought into the 
United States, but they had to be handled like eggs. The fila- 
ment, made by squirting a paste of tungsten powder and a 
binder through a small hole, then heating it, was extremely 
fragile. At the G-E Laboratory, Dr. William D. Coolidge im- 
proved this process, so that the filaments were considerably 


stronger. Though these lamps still had to be handled with care, 
and would not stand up under the vibrations of a trolley car or 
a railroad train, it was decided to start their manufacture, and 
the necessary equipment was installed. 

In the meantime Dr. Coolidge had solved the problem in an- 
other way. Most metallurgists had supposed that brittleness 
of tungsten was an inherent property that could not be over- 
come. But he found that it was unlike most metals, which, when 
once made ductile, become brittle as they are hammered, drawn 
through dies, and worked in other ways. By hammering and 
drawing hot tungsten, it proved possible to make it into a fine 
wire, of great strength and ductility. Because of the advan- 
tages of ductile tungsten, half a million dollars' worth of ma- 
chinery for making squirted filament lamps, together with a 
stock of unsold lamps of the same value, was scrapped, and 
the new lamp went into production in 1911. 

Though these lamps would stand vibration, and were suit- 
able for all kinds of service, they still showed a progressive 
blackening, and this was conquered by the work of another of 
the brilliant scientists whom Whitney had gathered round him 
Dr. Irving Langmuir, whose scientific achievements were to 
win him the Nobel Prize in Chemistry in 1932. 

It has been supposed that the blackening was connected with 
the slight amount of air that remained in the bulb, and that a 
better vacuum was the answer to the problem. But at that time 
a better vacuum could not be produced. So Dr. Langmuir 
turned to a research technique that has often proved effective. 
In an address to the American Chemical Society, he once said: 

When it is suspected that some useful result is to be obtained by 
avoiding certain undesired factors, but it is found that these factors 
are very difficult to avoid, then it is a good plan to increase deliber- 
ately each of these factors in turn, so as to exaggerate their bad effects, 
and thus become so familiar with them that one can determine 
whether it is really worth while avoiding them. 

For example, if you have in lamps a vacuum as good as you know 
how to produce, but suspect that the lamps would be better if you 
had a vacuum, say, one hundred times as good, it may be the best 


policy, instead of attempting to devise methods of improving this 
vacuum, to spoil the vacuum deliberately in known ways. You may 
find that no improvement in vacuum is needed, or just how much 
better the vacuum needs to be. 

Dr. Langmuir admitted that: 

During these first few years, while I was having such a good time 
satisfying my curiosity and publishing scientific papers on chemical 
reactions at low pressures, I frequently wondered whether it was 
fair that I should spend my whole time in an industrial organization 
on such purely scientific work, for I confess I didn't see what appli- 
cations could be made of it, nor did I even have any applications in 
mind. Several times I talked the matter over with Dr. Whitney, saying 
that I could not tell where this work was going to lead us. He replied 
that it was not necessary, as far as he was concerned, that it should 
lead anywhere. He would like to see me continue working along any 
fundamental lines that would give us more information in regard to 
the phenomena taking place in incandescent lamps. 

Two years' work led to the conclusion that it was simply 
evaporation from the filament that made the bulbs blacken, 
and that improving the vacuum would not be of any help. 
Though this was a negative result, it was a profitable one, be- 
cause it showed what was not the road to be followed, and 
saved wasting further time in that direction. 

So taking gas out would not help; all right, then, how about 
putting gas in? Of course it would have to be an inert gas 
one that did not react with the hot tungsten. Nitrogen would 
do; or better, one of the so-called "noble" gases, like argon, 
present in minute amounts in the atmosphere. He tried this, 
and found that even if the gas in the bulb were as dense as the 
atmosphere itself, there was a greatly decreased rate of evapora- 
tion of the metal. But the gas conducted heat away from the 
filament more rapidly than the vacuum, and this caused a loss 
of efficiency. Again came fundamental research, this time on 
the loss of heat from wires in a gas. 

By making the filament large, it developed, there was not 
much more loss of heat, yet with more surface the larger fila- 
ment gave more light. But a large filament conducts more elec- 


tricity; consequently it could only be used in a high-power 
lamp. Then Langmuir found that a finer filament, with the 
higher resistance needed, could be coiled into a helix or "spiral." 
If the helix were tightly coiled, so long as they did not touch, the 
high resistance remained, yet so far as heat loss was concerned, 
it was the diameter of the coil, rather than of the wire, which 
counted. Today the wire is often coiled, and then again coiled, 
and gas-filled lamps are used in all but the smallest sizes. 

From an efficiency in 1881 for Edison's lamps of 1.7 lumens 
for every watt of current used, and about 2.6 lumens per watt 
for his best lamps at the time that he thought they could 
not be improved this research has raised the figure more than 
400 per cent. The modern 40-watt Mazda lamp with which, 
perhaps, you are reading these words, gives 11.6 lumens per 
watt when it is new, dropping only slightly to 10.6 lumens per 
watt when about 70 per cent of its life is gone. In higher wat- 
tages efficiency is even greater. A 1500-watt lamp, for instance, 
gives 22.2 lumens per watt when new. It has been estimated 
that our lighting bills are several million dollars less every day 
as a result of Langmuir 's researches and he doubted their 
practical value! 


Incandescent lamps give their light from glowing solids. The 
light from a candle flame also comes from glowing solids, small 
particles of carbon, which deposit on a cold surface as soot 
when you hold it in the flame. The gas and oil flames are similar. 
So is the Welsbach burner with its mantle heated by a hot blue 
flame of gas a device which greatly improved the efficiency of 
gas lighting, and enabled it to hold on for a time despite the in- 
creasing competition of electricity. 

But an incandescent solid is not the only possible source of 
light the sun, and the other stars, are all gaseous, and their 
light comes from a glowing gas, hot, to be sure. However, a 
gas can be excited to glow without necessarily heating it; you 
can bombard it with electrons, for example. These knock other 


electrons out of their usual places in the gaseous atoms, and as 
they fall back light energy comes out. 

Aboult 1860 Heinrich Geissler, in Germany, sent electrical 
discharges of high voltages through glass tubes which con- 
tained minute amounts of air, or other gases. These Geissler 
tubes gave off light, but they were applied more for research, 
or for spectacular demonstrations, than for useful sources of 
illumination. But in 1904 an American, D. McFarlan Moore, 
introduced a light embodying similar principles. The first in- 
stallation, in a Newark hardware store, consisted of a glass tube 
1.75 inches in diameter and 180 feet long, going from one end 
of the store to the other and back. The tubes contained nitro- 
gen, from the air, at low pressure, or carbon dioxide. The latter 
was not as efficient as nitrogen, but it gave a fine white light. 

And about the same time Peter Cooper Hewitt, another 
American inventor, introduced the mercury-vapor arc lamp, 
in which a discharge through mercury vapor gave a brilliant 
and quite efficient blue-green light. Because its colors were 
those to which the photographic emulsions of that day were 
most sensitive, it was used widely in photographic studios. It 
also gives out large quantities of invisible ultraviolet rays, 
especially if the tube is of quartz, instead of glass which is partly 
opaque to them. 

There are many substances called phosphors, which glow 
with visible light when struck by ultraviolet rays. This happens 
because the electrons in the phosphors that are knocked out of 
their usual orbits do not fall back in one step; otherwise the 
light they gave off would be just as invisible as that which they 
received. Instead, they may fall back in two, or even more, 
steps, and then may give off radiation which happens to be in 
the range to which the eye is sensitive. This is called fluores- 
cence. In addition, some of these phosphors show phospho- 
rescence by continuing to glow for a time, perhaps measured 
in hours, after the exciting light has been turned off. This re- 
sults from a delay in the return of the electrons to their cus- 
tomary positions. 


To remedy the lack of red light from the mercury-vapor 
lamp, its inventor had the ingenious idea of using fluorescence. 
He coated the reflector of the lamp with a phosphor called 
rhodamine. Excited not by ultraviolet but by visible green rays 
(which the lamp gives off copiously), rhodamine glows with a 
brilliant red. Thus, the lamp gave off the green light, the re- 
flector filled in with red light, and the mixture was some ap- 
proach to white. The main difficulty with the system, however, 
was that the rhodamine faded quickly. 

The red light from neon gas, excited by an electrical dis- 
charge, has become very familiar, though not for illumination 
so much as for advertising signs. However, units have been 
made combining a mercury tube with a neon tube, and these 
give a very satisfactory light because the neon supplies the 
missing red. 

However, mercury vapor itself may be made to give a white 
light if the pressure is great enough many thousands of 
pounds to the square inch. Such lamps are quite small, the ac- 
tual opening in the tube being not much bigger than a pin, 
though the wall of the tube is thick to withstand the pressure. 
It is usually made of quartz, which is less likely than glass to 
melt at the high temperature obtained. But even quartz will be 
melted in the most powerful of these high-pressure mercury 
lamps, and so the most potent are surrounded by jackets 
through which water flows to cool them. 

Among lamps giving white light, these are the most efficient 
yet produced commercially, for they yield as many as 65 lu- 
mens per watt, which gets more than a quarter of the way to 
the 225 lumens per watt theoretically possible for a white light. 
They are not yet suitable for home lighting, though that may 
well be a forthcoming development. They are used for out- 
door lighting, at airports, for example, or in motion picture 

Dr. N. T. Gordon, a G-E scientist, has devised a novel applica- 
tion of them, as shown in the picture, for testing glass and other 
transparent materials for defects. The light is so nearly con- 


centrated to a point that when a beam shines on a piece of 
glass the shadow on a screen a short distance in back of it 
shows clearly, by wavy dark areas, the irregular areas. Differ- 
ences in temperatures in a liquid produce similar effects the 
illustration shows an ice cube melting in water, the cold, heavy 
water from the ice flowing to the bottom. That is what happens 
in your highball, and shows why it gets weaker as you let it 

The most efficient lamp yet devised for general lighting pur- 
poses is one that goes back to the principles of fluorescence. 
These lights are rapidly becoming very popular; you see them 
in restaurants, in barbershops, in stores, as well as in many new 
homes tubular lamps usually giving a cool, white light. In 
the tube are two filaments from which electrons are emitted. 
It contains small amounts of argon and mercury vapor. First 
the electrons make the argon glow, and this starts the mercury; 
so if the tube were of clear glass, all you would see would be 
the faint blue light of the glowing gas mixture. 

In actual use, however, this blue light never escapes. It hap- 
pens to be rich in ultraviolet rays, and these fall on the solid 
phosphors which line the tube. They in turn convert the in- 
visible to visible light, and that is what comes from the tube for 
illumination purposes. Because the wavelength of the ultra- 
violet light from the mercury vapor in such a tube has just 
the value that produces the maximum fluorescence from the 
phosphors used, these lamps are highly efficient; and a 15-watt 
fluorescent lamp will give as much light as an incandescent 
lamp of from 40 to 60 watts, depending on color. 

If the phosphor is basically zinc silicate, the resultant light 
is green, a color to which the eye is highly sensitive, and the 
efficiency then is about 70 lumens per watt. But, again, people 
want white light. Beryllium added to the zinc silicate makes its 
light more yellow and orange. Compounds of tungsten give 
light more blue, while a compound of cadmium and silicon 
makes red light. Thus fluorescent lamps are available for light 


of various colors. By mixing these different phosphors in proper 
proportions, each can be made to contribute to the spectrum, 
and white light is the result. This, however, is at the expense 
of efficiency, but even then the yield is 52 lumens per watt. 
These figures apply to lamps 48 inches long, a size commonly 
used. Smaller ones are also sold, but they are not quite so ef- 
ficient, though their performance is well in advance of incan- 
descent lighting. 

Another advantage of fluorescent light is that, when neces- 
sary, it can be kept at low intensity, and since the ultraviolet 
that excites it is invisible, the total amount of light is also very 
low. For instance, in a motion picture theater, you may want 
to have a sign giving, possibly, emergency instructions. If the 
sign is printed in the usual way, the whole card must be illu- 
minated, and a great deal of light is reflected from the back- 
ground. But the Continental Lithographic Corporation, in 
Cleveland, has introduced a line of fluorescent inks. A sign thus 
printed can be flooded with enough ultraviolet so that the let- 
ters shine with sufficient brightness to be read; but no other 
light is seen. Such a method is useful for blackouts, as has been 
demonstrated in England. Road signs, too, or even a guide line 
down the middle of a road, might be painted with phosphors. 
Then, by equipping automobiles with ultraviolet '^headlights," 
they could get around in the dark. 

By painting the walls of a factory with a phosphorescent ma- 
terial, they will be charged, so that in case of power failure 
there will be enough glow for a time to enable the workers to 
find their way about. Panic, from being plunged into sudden 
darkness, would be prevented. Dr. E. W. Beggs, of the West- 
inghouse Electric and Manufacturing Company, has said that 
such a painted wall might be made to glow for many hours, 
with the intensity of full moonlight, by setting off in the room 
a single photon 1 ash bulb. 

And if a room is so provided with a phosphorescent or a 
fluorescent paint, an obvious step would be to place in it several 


ultraviolet lamps, their radiation directed to the walls. This 
would give a uniform glow from a very large source, entirely 
free from glare; yet its brightness could be sufficient to allow 
any kind of work or reading. By using a combination of various 
phosphors, as for the fluorescent lamps, white light, or any 
color, could be secured without difficultly. 

Fluorescence has proved a great boon to the aviator, par- 
ticularly the pilot of a bomber on a night flight, or of a fighter 
plane, out after an enemy bomber. In either case, the pilot's 
eyes must be adapted to the dark, so that he can see as much 
as possible. Yet he must be able to read his instruments. If these 
are illuminated by a general lighting, even a faint one, there is 
a good deal of light spilled over. But if the pointers and dials 
of the instruments are painted with phosphors, and if the panel 
is flooded with ultraviolet, these alone are faintly visible, yet not 
bright enough to destroy the flier's dark adaptation. Essentially, 
this method is similar to the radium painting often used for 
alarm clock or watch dials. There we see a phosphor mixed with 
a radioactive substance, which excites it to glow. For extensive 
installations, the separate excitation with "black" light is less 
expensive, and admits of more accurate control. The bright- 
ness of the ultraviolet lamp, for example, may be varied, and 
the brilliance of the instruments can be always kept at the low- 
est possible intensity. An airplane instrument board, as seen by 
normal light and by fluorescence, is contrasted in the illustra- 

In order to provide the exciting rays, a lamp similar to a 
fluorescent lamp without its lining is used. Or instead, it may 
be an actual fluorescent lamp, for some phosphors them- 
selves give off ultraviolet rays. That is, they may be excited 
by rays of wavelength 2600 (measured in Angstrom units, 
about 1 /254,ooo,ooo inch) and the rays given off may be longer, 
though still below the 4000 figure that is the wavelength of 
the deepest violet light the eye can detect. Then these rays 
fall on the instruments, and they give off visible, and useful, 


light. It is never possible for fluorescent radiation to have a 
wavelength less than that of the light, either visible or invisible, 
that excites it. For that reason, though ultraviolet rays may be 
made visible by this effect, we cannot use it for seeing infrared, 
the rays beyond the other end of the spectrum the heat waves 
that are too long to affect the eye. Consequently, as described 
on page 164, more indirect means are required to pick up and 
detect the heat radiation from, for example, the hot exhaust 
gases of an airplane at night. 

Electric lamps giving off ultraviolet, rather than visible, rays 
have another increasingly important use. They are powerful 
killers not only of germs, but also of those still smaller disease- 
bearing agencies, the viruses, which float in the air and are 
responsible for many epidemics. 

Man, and even animals before he appeared on this planet, 
made use, unknowingly, of ultraviolet rays for antiseptic pur- 
poses. These came then, as they do now, in the rays from the 
sun. They are responsible for the sunburn for which you lie on 
the beach in summertime. Vitamin D, the absence of which in 
the diet results in rickets, is formed by the action of ultraviolet 
rays on ergosterol and related compounds, which are present 
in the body and in certain foods. To supply this vitamin Dr. 
Harry Steenbock, of the University of Wisconsin, invented a 
process for "irradiating'* foods by ultraviolet radiation. Though 
he was granted a patent on this important process, its benefits 
have not been to his personal advantage, for he assigned the 
rights to a research foundation at the University of Wisconsin, 
which has been the donor of funds for much other research of 

In such irradiation ultraviolet electric lamps are used, with a 
mercury discharge in a quartz tube; for glass cuts out the 
shorter waves, which have the most effect. However, for germi- 


cidal purposes a type of mercury lamp in a tube of special glass 
is often used. One form of such light is the Westinghouse 

A century ago hospital operations frequently brought death 
instead of life to the patient, so great was the danger of in- 
fection. But in the middle of the nineteenth century Lord 
Lister applied Pasteur's germ theory of disease when he showed 
that the gangrene which followed an operation was caused by 
germs carried on the hands and instruments of the surgeon and 
his helpers. Lister used carbolic acid as a sterilizer, and sprayed 
the same antiseptic into the air in the vicinity of the incision. 
Such measures were of great efficacy; much of the danger of 
surgery was eliminated; but there still remained, however, 
some source of infection even after the most elaborate precau- 
tions were taken. Out of 1735 surgical cases a few years ago at 
one large hospital, 206 patients showed traces of infection and 
19 died, despite what seemed the best possible treatment. Dr. 
Deryl Hart, professor of surgery at Duke University Medical 
School, showed that the cause was in organisms which floated 
through the air. By placing ultraviolet lamps above the operat- 
ing table, the air was sterilized, and an infection rate of 11.9 per 
cent was lowered to less than a quarter of one per cent. 

Tests made in Philadelphia schools by Dr. M. W. Wells and 
Dr. W. F. Wells during the winter of 1940-41 showed that 
ultraviolet lamps produced, apparently, a notable reduction in 
the number of cases of measles, despite an epidemic which was 
the worst in several years. Measles is caused not by a germ but 
a virus, one of those mysterious agencies that are too small to 
be seen with the ordinary microscope. Probably the common 
cold has a similar origin. Measles usually attacks the younger 
children, yet, in one school where ultraviolet lamps flooded 
the rooms of the primary grades, this was reversed. The school 
had more measles cases than in any of ten previous years, but 
this was owing to cases in the upper classes, which had far 
more than the younger children. 

Dr. William F. Wells suggests that this would have great 


possibilities for preventing epidemics among soldiers, quartered 
in close contact in barracks, recreation rooms and mess halls. 
The same method appears to be of value, too, in preventing 
colds and influenza. 

Still another very efficient light, which you encounter with 
increasing frequency illuminating roads and bridges, is one 
which shines with a not unpleasant golden-yellow color. Here 
the light comes from sodium vapor, likewise made to glow by 
an electrical discharge. Practically all the light emitted is visi- 
ble; such lamps give as much as sixty lumens per watt, while 
in the laboratory, by protecting the lamps very effectively from 
heat loss, five times this output has been attained. 

The advantage of sodium was known a long time before it 
was used. However, ordinary glass is rapidly attacked and black- 
ened by hot sodium atoms; and it was not until the Corning 
Glass Works found a sodium-resistant glass, which could be 
coated on the inside of a bulb made of a less expensive glass, 
that the way to its utilization was cleared. 

The sodium lamp is about the size and shape of a rolling 
pin, without handles at the ends. It contains some neon gas and 
a small bit of sodium metal. When the current starts flowing 
the neon glows, and for about five minutes it shines with a red 
color. But when the heat of the neon glow has vaporized the 
sodium, its vapor starts to shine with characteristic yellow color. 
Since there are about 10,000 times as many sodium atoms as 
there are neon, the red glow is completely lost. The lamp gets 
quite hot, and to avoid losses through radiated heat the bulbs 
are surrounded by a transparent thermos bottle. In very cold 
places even this is not adequate, and for such circumstances a 
second, larger, thermos bottle, outside the first, is used. 

Because of their color and their slow starting, these lamps 
may perhaps never be used for indoor lighting, but they have 
proved ideal for highways, and considerably cheaper to oper- 
ate than incandescent lamps. Many installations have resulted 
in a significant reduction in accidents along their routes. Prob- 
ably this follows from the fact that their color is one to which 


the eye is highly sensitive, and vision becomes more acute than 
with white light. 

There is a common idea that the light of the firefly is an ideal 
which science should strive to emulate. It is true that the fire- 
fly's light is almost entirely of a green color to which the hu- 
man eye is very sensitive. No one, however, seems to have 
asked the firefly whether he sees this color best. As it gives off 
light of only this color, none of its energy is wasted as heat or 
ultraviolet rays which we cannot see. 

But this does not mean that the light of the firefly is efficient, 
in the same sense that we have talked about the efficiency of 
incandescent lamps. We want as much light as possible for the 
energy, in the form of electricity, that we put into our lamps. 
It has been rather hard to calculate how much energy the firefly 
uses for each lumen that he emits, but he seems to be not quite 
as efficient as an incandescent lamp. In the case of one variety 
of luminous bacteria, Dr. E. Newton Harvey, of Princeton 
University, a leading authority in the field of animal light, 
found that it gave only about one lumen per watt, or an ef- 
ficiency poorer even than the first incandescent lamp. Dr. 
Harvey's researches have shown that such light comes generally 
from the interactions of two compounds, luciferin and luci- 
f erase, the latter belonging to the class of enzymes. 

Chemists have found the way to make such chemical light 
in a manner comparable to the firefly's process. They use a 
rather rare and expensive chemical known as "three-amino- 
phthalhydrazide," in an alkaline solution. When chemicals sup- 
plying oxygen are added there is a chemical change and a 
bluish green light is emitted. This is cold light; in fact, it works 
perfectly well if ice cubes are floating around in the solution. 

Unless there is a continual supply of the chemicals, such light 
lasts only a few minutes; and it has been estimated to cost 
about 25 million times as much as Mazda lamp light. If one has 


an electric-light bill of a dollar a month, a mere $25,000,000 
would be the cost of providing equal illumination by the fire- 
fly's method. So probably chemical light is not going to replace 
electric light at least not in the immediate future! 

XVII. Pictures of the Future 

In the rush of world-shaking events in the year 1939 an 
important anniversary was, for the most part, neglected. This 
was the centenary of the birth of photography, for it was in 
1839 that Daguerre in France, and Fox Talbot in England, an- 
nounced their inventions. Yet the closing fifteen years of the 
first century of photography was perhaps the period in which 
it made its greatest advance, both technically and in popularity. 
Since 1939 that advance has continued, with the further stimu- 
lation of war. High-speed lenses then combined with films of a 
new range of sensitivity in making possible photographs under 
conditions that would have been hopeless in earlier days. New 
processes now permit the amateur to take color photographs in 
an ordinary camera, and to secure prints of these pictures. Mo- 
bile lighting units, for exposures as short as % 0,000 of a sec- 
ond, making clear pictures of rapidly moving objects, are com- 
ing to be an essential part of any well-equipped studio. In place 
of the flash powder of former times which filled a room with 
smoke when used, our modern photographer has the convenient 
flash bulbs. Some of them even emit their total radiation in in- 
visible infrared "light" and, with the use of specially sensitized 
films, literally allow pictures to be taken in the dark. 

Motion pictures, which are after all a direct outcome of 
photographic processes, have had a comparable advance. Most 
epoch-marking was the introduction of sound pictures, which 
succeeded after several earlier and still-born attempts. New 
color processes brought to the motion pictures far greater real- 
ism than ever before. And movies at last came into the home, 
first in black and white, later in color, which is now the more 

All photography depends basically on the action of light on 



silver salts chiefly silver bromide. Though exactly what hap- 
pens is still not entirely understood, it seems that, when light 
acts on a small crystal of silver bromide contained in the sensi- 
tive emulsion, minute particles of silver inside the crystal are 
freed from their bond with the bromine. This was demonstrated 
by two French scientists who shot electrons and X-rays through 
exposed but undeveloped silver-bromide crystals. They found 
the beam to be bent as by metallic silver, which is different 
from the effect that the bromide has on the rays. At the East- 
man Kodak Research Laboratory the crystals have been ex- 
amined with the electron microscope. Crystals exposed to as 
much light as used in practical photography show many tiny 
particles, and those of silver which form the latent image have 
not been identified. But, with much longer exposures, particles 
of silver inside the crystals are readily seen, magnified 25,000 

When the exposed film is developed, more of the silver bro- 
mide is reduced to metal formed around the nuclei already 
present. In the places where no light struck, none of these silver 
particles are formed, no such nuclei are provided, and the white 
silver bromide in these portions remains unreduced. After de- 
velopment, this unchanged silver bromide must be removed. 
That is done in the fixing bath, with a chemical called sodium 
thiosulfate. Anyone who has ever developed a film, or seen it 
done, is familiar with the process, and knows how during fixa- 
tion the film clears up from its milky appearance, leaving the 
negative with light areas of the picture formed by black masses 
of silver grains. 1 

When the silver particles of developed and fixed film are 
examined under the ordinary light microscope, they appear as 
masses of coke. But when two Kodak scientists, C. E. Hall and 
A. L. Schoen, first examined them with the electron micro- 

1 The paper on which the negative is printed has an emulsion which is similar 
to that of the film, though less sensitive to light. Bromide papers, used for enlarg- 
ing, contain silver bromide, as their name implies. Those used for contact print- 
ing, still slower, are generally of silver chloride, or a mixture of chloride and 


scope, they found tangled masses of threads and ribbons. It 
would appear that development causes the silver to build up on 
the nuclei in one direction at first, thus forming filaments which 
wind around inside the silver-bromide crystal. 

The ordinary emulsion is sensitive only to the blue and violet 
colors in light, and to the ultraviolet rays. That is why it can be 
developed by the use of a red darkroom lamp. But a number of 
years ago a German chemist named Vogel found that mixing 
dyes with the emulsions in manufacture sensitized them to 
other bands of color. A blue dye appears blue because it ab- 
sorbs yellow (and other colors). The emulsion to which it is 
added becomes sensitive to yellow light. To sensitize to green 
or blue-green, a red dye should be used; while a green dye 
should sensitize to red or bluish -red. In general, this principle 
is the basis of the preparation of color-sensitive plates. 

With the limited number of dyes which, in Vogel's time met 
the requirements for permanence, the orthochromatic plate 
was produced. This extended the sensitivity range to include 
the yellow of the spectrum. In 1904 the introduction by a 
German manufacturer of dyes called "cyanines" made possible 
the panchromatic plate, which extended the sensitivity into the 
red. British researches between 1918-1928, into the chemistry of 
these dyes, laid the groundwork for still further increases in 
sensitivity 7 range. No longer are photographers limited to tak- 
ing photographs in a band of color including only about a third 
of the spectrum visible to the eye, as they were in 1875; now 
the spectrum available to the photographic process covers about 
four times the extent of wavelengths that the eye does. And 
since 1925 the range into the infrared has been increased many 
fold. Scientific photographers find these methods of particular 
value, especially since it is now possible to sensitize selectively 
to certain regions in the visible or invisible spectrum. 

As a result of this ability to sensitize plates to any part of the 
visible spectrum, color photography became practicable. Op- 
tically, red, green and blue are fundamental; and by mixing 
lights of these colors, any other color of the spectrum may be 


reproduced. As early as 1890 a pioneer in color photography, 
Frederic E. Ives of Philadelphia, had put on the market a suc- 
cessful process. He would take three separate pictures of the 
same subject, one with green light, one with blue and one with 
red. Because of the low sensitivity of emulsions of that period 
to red light, that exposure had to be very long; and since the 
photographs were made successively, the method was not 
adapted to photographing moving subjects. 

From each of the three negatives, Ives would make a print 
on another plate that is, a lantern slide. These were placed 
in a triple projecting lantern, with three separate sets of lenses, 
and thrown on a screen together, with the three images coin- 
ciding. Over the slide taken with red light was a piece of red 
glass; the green slide was shown in green light and the blue 
in blue light. Thus, on the screen, the combinations of these 
colors gave all the hues of the original subject. Another inven- 
tion by Ives was arranged so that, instead of projecting the 
picture, a person could look into an apparatus and the three 
pictures would be combined. In addition, this showed the scene 
in stereoscopic relief with a realism that no other still photo- 
graphic process has ever surpassed. 

Such a process as that of Ives is called additive, because it 
starts out with darkness on the screen and adds the colors to 
it. But the most commonly used methods today are subtractive 
that is, they start with white light and take colors away. But 
obviously, if you take away the same colors that you would 
supply in the additive process, the results are not the same. 

Suppose we have three slides, such as those used in Ives' 
triple projector. It might seem that we could dye each with the 
same color used to project it, lay the three in a pile, and a single 
color picture would result. But this will not work. The dye 
would be uniform over each film, and when they are together 
would stop all light from passing through. However, there are 


methods of forming dye images processes in which the silver 
image, the opaque part of the picture, is replaced by dye, leav- 
ing clear and uncolored the areas originally transparent. If such 
dye images be formed, using red for the picture taken in red 
light, blue for the one made in blue light and green for that 
which shows the greens in the original, and if these are laid to- 
gether, the picture will be in color. But the colors will be 
complementary to those of the original. The blue sky will be 
orange, a red rose will appear bluish-green, and green leaves 
will be violet. 

However, if the individual dye images be made in colors 
themselves complementary to those used for taking the re- 
spective negatives, the three can be combined to give a faithful 
reproduction of the scene. Take the red rose, for example, and 
to make it simpler, imagine that it is in a white vase, and photo- 
graphed against a black background. On the red-sensitive slide, 
which has the bluish-green dye image, the rose itself is clear. 
Since it looked dark to the green image, this slide, printed in 
magenta, a mixture of red and blue, has color where the rose is 
shown. Likewise the blue slide, which is printed in yellow, 
shows the rose in that color. In all three the vase is clear, and 
in all three the background is in the color of the dye. 

Now, when these films are laid one on top of another and 
examined against a white illumination, the white light goes 
through the vase image without interruption, and it appears 
white. The background stops all the rays and appears black. 
The rose appears in the light that penetrated the magenta and 
yellow, and consequently is red, because the yellow dye is not 
a pure spectral yellow but lets through some green and red as 
well. Only red can get through both magenta and yellow. 

The case is similar with other colors. A green leaf, for in- 
stance, would appear in light that was able to pass through 
both the yellow and blue-green dyes, and only green can do 
this. If there is also a blue flower in the picture, this would be 
formed by light that had been transmitted both by the blue- 
green and magenta dyes. 


There are simpler ways, however, of taking the three images 
than one after another in an ordinary camera. Professional color 
studios often use "single-shot" cameras. One of these has a 
single lens, but three plate or film holders, and two mirrors, 
each only partially silvered, which reflect about a third of 
the light and transmit the rest. These mirrors divide the light 
into three parts and feed it, through appropriate color filters, to 
the three plates or films. From these three negatives, trans- 
parencies or prints can be made by various methods, all of 
which use essentially the principles described above. Still sim- 
pler than the three-way camera is the "tripack," three unex- 
posed films, of proper sensitivity, held tightly together and ex- 
posed at once. Since the light has to pass through the first film 
to get to the second, and through both the first and second to 
reach the third, the back one is apt to be blurred. But if the 
three are very thin, and in intimate contact, there is no chance 
for blurring. In the same way. you can lay a piece of waxed 
paper over printing and read it clearly, but if you hold it a short 
distance above, the printing is blurred. 

This is what is done in the most popular of modern color 
processes Kodachrome. Three photographic emulsions are 
placed on the same film and, to aid in the selective effect for 
the different colors, screening dyes are added to them. This 
process was invented by two scientists at the Kodak Laboratory, 
Leopold Godowsky, Jr., and Leopold D. Mannes, who devised 
a most ingenious scheme of developing. As originally intro- 
duced in 1935, the film was first developed, and in all three 
emulsion layers the latent image turned to silver. But, without 
fixing, these images were dissolved away with a special bleach- 
ing solution. Then the film was exposed to light, to make the re- 
maining silver bromide developable. Next, this was developed, 
but in a peculiar kind of "coupling" developer, first applied by 
Rudolph Fischer in 1912. The effect is to form, along with the 
silver image and at the same time it is developed, a dye image 
as well. 

After the original silver image had been bleached, and the film 


had been re-exposed to light, it was treated with a coupling de- 
veloper which formed a blue-green image in aU three layers. 
Next the film was subjected to a bleach which was able to pene- 
trate only the top two layers, where it converted these images 
back to silver bromide and destroyed the dye, though leaving 
the bottom layer unaffected. Then the film went to another 
coupler developer which deposited silver and a magenta image 
in each of the top two layers. But again it was bleached, this 
time with a chemical of such feeble penetration that only the 
top layer was affected, by having its dye destroyed and the 
silver converted back to the bromide. In the fourth and last 
development, a yellow image was formed in the top layer, to- 
gether with one of silver. Then another bleach was applied, this 
time able to reach all layers, but not to affect the dyes. It did, 
however, convert all the silver images back into silver bromide. 
Then, finally, the film was fixed, all the silver bromide dissolved 
away, and only the three dye images, properly placed with re- 
spect to each other and combining to form a color picture, 

All this sounds pretty complicated and so it is. One need 
not wonder that in putting Kodachrome on the market the East- 
man Company returned to the policy they had used when the 
first Kodaks appeared half a century ago "You press the but- 
ton, we do the rest/' But the accurate and efficient machines at 
Rochester did "the rest" and this process made popular color 
photography, in eight and 16 mm amateur movies, and in the 
35 mm film for miniature cameras of the Leica and Con tax 
type. Later, cut film was introduced for professional use, in 
sizes such as 8 x 10 inches, or even 11 x 14 inches. 

By this time, however, the original process had been simpli- 
fied to the one used today. The film is practically the same, and 
is developed first to convert all the exposed parts to silver. But 
then it is exposed, through the film base, to red light, which 
acts only on the unexposed part of the bottom layer. This is 
developed with a coupling developer that forms a blue-green 
positive image along with the additional silver image. Then 


the top of the film is exposed to blue light, and goes to a de- 
veloper with a coupler forming a yellow image. By this time 
the only undeveloped silver bromide remaining is that of the 
positive image in the middle layer. If a developer is made strong 
enough, it can convert even unexposed silver bromide to silver. 
Thus, the positive of the middle layer is developed with 
magenta-forming coupler. Next the three layers of silver are 
removed, and this leaves only the three dye images, all in the 
proper relation to each other. 

Until 1941 such color pictures were generally available only 
as transparencies. That is, they had to be used as lantern slides 
projected on a screen, or viewed by holding against a brightly 
illuminated surface. Only by somewhat difficult and expensive 
methods could they be made into color prints on paper. But 
in the summer of 1941 the Eastman Company began produc- 
tion of enlarged color prints, both from the 35 mm film and 
from the larger cut sizes. Essentially, the material used for these 
prints is the triple Kodachrome emulsion on a backing of white, 
opaque film, which has proved more satisfactory than paper. 

The original idea for a color process by coupler development 
involved incorporating right into each of the three emulsions 
the couplers which, in the process of development, would pro- 
duce the desired dyes. At that time it was found very diffi- 
cult to keep these couplers in their proper places, they tended to 
wander into other layers. However, after 1935 when Koda- 
chrome was introduced, the Agfa company in Germany 
brought out Agfacolor, which successfully used Fischer's orig- 
inal method. In the meantime Eastman scientists had devised 
another method, by which, as Dr. C. E. K. Mees, Eastman re- 
search director, described it in a lecture before the Franklin 

The couplers in their emulsion layers are not dissolved in the gelatin 
layer itself, but are carried in very small particles of organic materials 
which protect them from the gelatin and, at the same time, protect 
the silver bromide from any interaction with the couplers. When de- 
velopment takes place, the oxidation product of the developing agent 


dissolves in the organic material and there reacts with the couplers, 
so that the dyes are formed in the small particles dispersed through- 
out the layers. This process might be known technically as the 
"protected coupler" process. 2 

Perfection of color-photographic processes has also had an 
important military application, for with them can be penetrated 
much of the camouflage that would hide enemy territory in 
black-and-white photographs. Experts of the U. S. Army Air 
Corps stationed at Wright Field have been able to take brilliant 
color photographs from about three miles altitude, and can 
probably double this figure. A three-lens camera, each with ap- 
propriate filter, takes the three photographs simultaneously. 

Not always, however, is the resulting picture an accurate re- 
production of what the flier saw from the plane at the time 
the exposure was made; nor is this at all desirable. By using 
infrared-sensitive film for black-and-white photographs, it is 
possible to see through the haze (but not fog), though this 
disturbs the color balance in color photography. Using a process 
of trial and error, Army men have laid out accurately colored 
50-foot-long strips of felt on the ground and photographed them 
from various heights and under various atmospheric condi- 
tions. Thus they learn the particular combinations of films and 
filters that produce the best results under all circumstances. 

Even at night, color as well as black-and-white aerial photo- 
graphs can be taken. Brilliant-colored flash bombs are dropped 
that can be seen two hundred miles away. An electric eye on 
the plane, which is above and hidden in the glare, trips the 

2 In January, 1942, this process was placed on the market as Kodacolor, using 
again the name of the first successful amateur color-movie process, one which 
became obsolete with the perfection of Kodachrome. The films are now sold, in 
roll form, for all popular amateur-sized cameras, except those using 35 mm film. 
Developed by the company, the negatives not only are reversed in lights and 
shades, but also the colors are complementary, with yellow skies, and blue-green 
lips. But these can be printed on paper coated with a similar emulsion; then a 
second reversal of light and color values produces a correct reproduction of the 


shutter of the camera when the flash is at its height. Again 
the films and filters have to be carefully chosen, to balance 
with the color of the flash. 

Synchronized flashes have also become important in ordi- 
nary photography on the ground. The old flash powder, used a 
generation ago, consisted of powdered magnesium mixed with 
a chemical supplying oxygen to burn it. Using such powder the 
usual way, the camera would be set on a firm support, the shut- 
ter would be opened, the flash exploded, and the shutter closed. 
Devices for operating the shutter just as the flash went off were 
made, but did not work too well. 

At the end of the 1920s, in Germany, the photoflash lamp was 
introduced a glass bulb containing aluminum foil and filled 
with oxygen. An electrically operated fuse, which would work 
on the current from a battery or from the lighting circuit, set it 
off, and the burning aluminum gave a brilliant light all inside 
the bulb, which confined the smoke. Soon afterwards these 
were made available in the United States, and immediately 
flash powder became obsolete. Accurate and reliable synchro- 
nizing devices were perfected, enabling short exposures to be 
taken under any lighting conditions. They proved a great boon 
to newspaper photographers, who often use them to supple- 
ment daylight under conditions where a powder flash would 
not have been considered feasible. 

The ordinary foil-filled flash bulb starts to give out light 
about two-hundredths of a second after the current is applied 
to the bulb. About five-hundredths of a second later the flash 
is over. But the peak of illumination comes at about 0.035 sec- 
onds, and most of the light is emitted in a time considerably 
shorter than that of the whole flash. Smaller bulbs, which give 
less total light, operate more rapidly, while others have been 
made, containing aluminum wire instead of foil, in which the 
light is more evenly distributed over the entire period. 

The shutter has to be synchronized to operate during the 
time the flash is at its height. Naturally, the light that the bulb 
gives out before the shutter opens and after it closes is not 


utilized, and this limits the shortness of the exposure that can 
be given. For most work, however, this is not a serious limita- 

Working at the Massachusetts Institute of Technologv, Dr. 
Harold E. Edgerton and his associates invented a far faster 
flash that operates electrically. This has been introduced com- 
mercially by the Eastman Company as the "Kodatron speed- 
lamp/' Though Dr. Edgerton obtained shutter speeds as short 
as a hundred-thousandth of a second, this is not needed for 
ordinary work, and the Kodatron lamp gives a flash of %5oo 
of a second. A portable battery-operated model, just intro- 
duced, works at % 0,0 oo of a second. 

In such a lamp, electric current, raised to high voltage, 
charges a condenser in about ten seconds. Then this is very 
rapidly discharged through a tube containing the rare gases 
krypton and xenon, which glow with a light equal, in the case 
of the larger unit, to 50,000 forty-watt Mazda lamps. No shutter 
can operate in a time so short, and it does not need to; its speed 
needs only to be short enough to prevent any other light in the 
room from making an image. It opens, the flash goes off, and 
then it closes the flash itself providing the timing. 

Though the most spectacular results of such high-speed 
photography have been in stopping fast-moving athletes or 
dancers, or technical subjects like machinery in rapid motion, 
the lamp is proving useful for portraiture as well. When the 
first photographs of human beings were made, the subject had 
to sit still in bright sunlight for several minutes. In those days 
clamps were used to hold the victim's head stationary. As faster 
lenses and films were made, such instruments of torture were 
eliminated, but still exposures of as much as half a second 
were, and are, common in portrait studios, and usually today 
the subject has to "hold it." But with the Kodatron lamp, the 
subject may be moving as rapidly as he can, moving his hands, 
perhaps, in animated conversation. The lamp will stop him as 
the picture is made. This is particularly valuable for pictures of 
restless children and animals. 


Not only have lights made high-speed photography possible, 
but, to utilize them, the films must be extremely sensitive; and in 
the past few years the manufacturers have found various means 
of making films which give good pictures with amounts of 
illumination that would have been unbelievably small twenty 
years ago. Then speed in a film was obtained only at the cost 
of graininess. That is, in the sensitive film or plate, the silver 
grains were relatively quite large, producing a difference in 
results comparable to that between the pictures in this book 
and those in a newspaper. But now fast films, yet with fine 
grain, can be obtained. Combined with development which 
preserves this fine grain, big enlargements from little negatives 
can be made; and this has partly accounted for the popularity 
of the miniature camera, which can be so easily handled. 

Making pictures with short exposures in a room with or- 
dinary lighting, and without the use of a flash, is also aided by 
the fast lenses with which modern cameras may be equipped. 
The speed of a lens, which determines the amount of light that 
gets through to the film, is measured, as already mentioned, by 
the F value the ratio between the distance of the lens from 
the film when focused on far-away objects, and the lens' di- 
ameter. Twenty years ago an F 4.5 lens was the fastest gen- 
erally available; now F 2 or even F 1.5 is not unusual. Since the 
speed is proportional (inversely) to the square of the F value, 
an F 2 lens admits about five times the amount of light of one 
that is F 4. 

In astronomical photography the Schmidt camera 3 is now 
widely used. This gives a speed of even F. 1; and with it, Dr. 
Harlow Shapley, director of the Harvard College Observatory 
has predicted, will come the greatest contributions to astron- 
omy during the next decade. The Schmidt camera is not very 
well adapted to ordinary photography, but its high speed has 
made it invaluable for aerial photographs. Though details of 

3 Also referred to on page 200 in connection with its reverse use as a tele- 
vision projector. 


this camera have not been revealed, it is known that a Schmidt 
aerial camera is now being made in quantity for the Army Air 

The use of fine-grain film also has made possible an answer 
to the problem which confronts every librarian of preserving 
an ever-increasing mass of material. A large book can be photo- 
graphed, page by page, on a 35 or even 16 mm film. The grain 
is so fine that the film may be put into a special projector and 
viewed in the original size, or perhaps larger, with complete 
clarity. Banks use such a device, the Recordak, a product of the 
Eastman Company, to record every check they handle, thus 
providing, in small space, a permanent record of their transac- 
tions. In the U. S. draft lotteries the same device was used to 
record, in a form that could not be questioned, the order of 
drawing of the numbers. 

This system, called micro-film, has also aided soldiers at dis- 
tant stations to keep in touch with the folks back home. It was 
first used for the British troops in the Middle East. A descrip- 
tion prepared by the Eastman Kodak Company explains its 
working as follows: 

Tommy Atkins writes his letter on a special sheet measuring 8% 
inches by 11 inches and prints his address in block letters on a panel 
at the foot. The completed sheet is then photographed on a consider- 
ably reduced scale 1 / 2 of an inch by % of an inch, to be precise 
with a Recordak. The film is then dispatched by airplane, and upon 
arrival in England a 4-inch by 5-inch enlargement is made. It is then 
placed in a paneled envelope leaving only the address exposed. 

Seventeen hundred letters can be photographed on a single 100- 
foot roll of micro-film, at the rate of 40 to 50 a minute. The film weighs 
only YIQQ as much as the 1700 letters. 

The miniature film images are enlarged on a roll of continuous 
photographic paper and processed at the rate of 1200 letters an hour. 
An automatic chopper, actuated by a photoelectric cell, separates the 

The great advantage of this method is ihe saving in weight. 
The first 50,000 Airgraph letters, which would have weighed 
over 1600 pounds if they had been written in the ordinary way, 


used instead only 13 pounds of film. The next 85,000, instead of 
1.5 tons, weighed only 20 pounds. This made it possible to send 
them all the way by air. Ordinary air mail from the Middle 
East, which costs more, has to be carried a considerable por- 
tion of the distance by sea, and takes as much as five weeks on 
the route, while the Airgraph letters are delivered in ten days 
or less. The same method was later applied for the benefit of 
U. S. troops in distant lands. 

The motion-picture industry has shared greatly in the im- 
provements in films and lenses that have so aided still pho- 
tography, but the most significant change it has had in the past 
fifteen years has been the complete adoption of sound. It is 
hard to realize today that it was only as recently as August 21, 
1926, that Warner Brothers released in New York their first 
feature sound picture Don Juan, with the sound on 16-inch 
phonograph discs. These were recorded and reproduced with 
electronic tubes, which made it possible to drive the record at 
the projector and to carry voice currents over wires to loud 
speakers in back of the screen the point from which the 
sounds must emanate. Earlier processes of sound pictures, 
where the record had to be played close to the horn through 
which the sound was thrown, required complex synchronizing 
arrangements to keep record and film in step. But with the 
Vitaphone, the name given to Warner Brothers* method, the 
record was driven by the same motor that ran the projector, 
and both were controlled by the same operator. 

Since then recording on the film itself has completely taken 
the place of the discs. The only use for the latter in sound 
movies is to make play-backs. That is, when a scene is taken, 
the sound is recorded not only on film but on a wax disc as 
well. This can be played back immediately to the cast and 
directors. If not satisfactory, the scene can be played over again 
while everything is ready. 

There are several main steps involved in making a sound 


film. The sound is picked up through a microphone, just as if 
it were going to be broadcast. Then it is amplified and operates 
some sort of light valve, which varies, in step with the current, 
the amount of light passing through; or else it controls the 
brightness of a special kind of lamp. In either event a changing 
light, modulated by the original sound, falls on the edge of a 
moving film. When developed, this shows either a band of 
light-and-dark strips or a white one of varying width. Though 
usually the sound record, except in news reels, is recorded 
separately from the film on which the scene is photographed, 
the sound track is printed alongside the picture in the positive 
to be projected. Thus there is no possibility of sound and 
picture getting out of step. In the projector there is a "sound 
head" through which the film runs after the picture has been 
thrown on the screen. A bright light is focused sharply on the 
sound track; on the opposite side is a photoelectric cell. The 
varying current from the cell is amplified, and operates the 
loud speaker. 

With sound and color together, the motion pictures have ac- 
quired a new degree of realism. Technicolor is the color process 
most used in the theater. By means of a prism serving as a 
"beam-splitter," light from the lens is divided into two parts. 
One is reflected to the side and falls on one film, while the 
rest, which passes through the prism, reaches a bipack two 
more films which run through the camera with emulsions in 
contact. Filters, and films of different color sensitivity, sort out 
the three fundamental colors, so that one film records each. 

From each negative is made a positive film with an image in 
colorless gelatin which is able to absorb dye. Each film is dyed 
and then used, like a rubber stamp, to print or transfer the 
color to another film. By thus printing the three, one above 
another, the full-color picture is obtained. Actually the film on 
which these are applied has a faint silver image to aid in 
accurate registration of the colors. The sound track is printed 
in the usual way, and is also formed of silver. 

For some motion-picture effects, it is desirable to show 


sharply only actors and objects at about the same distance from 
the camera; but there are other cases where very close and very 
distant ones should all be focused equally well. Orson Welles, 
in Citizen Kane, made effective dramatic use of this method. 
But in using it optical difficulties are encountered. A lens of 
small F value (i. e., a fast one) has very little "depth of focus/' 
Welles had to have his cameramen use their lenses at high F. 
values; and to overcome the loss of light, the illumination had 
to be very intense. 

Recently two inventions have been made which allow such 
results without disturbing the lenses' speed. One was invented 
by Dr. A. N. Goldsmith, and can be used only with artificial 
light. The other, invented by Dr. L. M. Dieterich and improved 
in practice by D. Stanley Smith, is called the "Electroplane" 
camera, and works out of doors as well. 

To change the focus from near to far objects, the distance 
between lens and film must be changed. The nearer an object 
is, the farther out the lens must extend. In the Goldsmith 
process the lens vibrates back and forth, making a complete 
travel for each picture. The illumination of the studio changes 
in step, so that when it is focused on the foreground, the fore- 
ground is lighted; as the lens moves in and the middle distance 
is in focus, that gets the light; and then the far distance is 
lighted and focused. 

It might be thought that one need not bother about the 
lighting; that the vibrating lens might be used out of doors as 
well. The trouble is that the size of the image changes. As the 
lens moves out to shift from far to near focus, the image of 
distant objects, though they become blurred, also become 
larger; and the result in the finished film is a halo around them. 

Dr. Dieterich, in 1933, devised a lens, consisting of several 
pieces of glass, that could change focus without changing the 
size of the image. In its latest form the lens has four elements, 
and only the second, which is concave, is moved. Its total travel 
is about a seventy-fifth of an inch. Mounted like the sound- 
producing element of a loud speaker, it is vibrated electrically, 


at a speed determined by an electronic control. The best re- 
sults, it is found, are obtained when the lens makes four 
complete sweeps for each picture. The sharp images mask out 
the fuzzy ones, with which they exactly coincide, and the film 
shows near and distant objects all sharply defined. 

But a sound film, even though it be in color and taken with 
such a device, is still only a picture when it is projected. To 
achieve complete realism it would have to be in stereoscopic 
relief. This has been done very expertly, as those who saw the 
stereoscopic film in the Chrysler exhibit at the New York 
World's Fair will well recall. 

To take a stereoscopic film, a double camera, the lenses 
located as far apart as the two eyes, must be used. One film 
will show the right eye's view, the other the left eye's. The 
trouble comes in letting an audience view these films, for when 
both are projected together the result is merely a blur; each 
eye sees both pictures. To obtain relief, the right eye must see 
only the right picture, the left eye the left. One method used 
in the past to do this required the use of colored glasses, a red 
one over the right eye, a green one over the left. Similarly 
colored filters are placed over the lenses of the two projectors, 
and each eye sees the picture in its respective color. 

The Chrysler film used Polaroid screens to do the same thing, 
eliminating the red and green filters which would have inter- 
fered with the colors of the picture itself. These screens are 
made of a material which polarizes light. Unlike ordinary light, 
which vibrates up and down, from right to left horizontally, 
and in all other directions, polarized light vibrates in but a 
single plane. To the naked eye it seems no different from un- 
polarized light. But the screen acts like a picket fence and, in 
one position, only vertical vibrations can get through. If, be- 
yond, there is another such fence with the pickets upright as 
in the first, the vibrations can get through this freely. But if 
the second fence has the pickets horizontal, this stops the 
waves that got through the first and none penetrates the 


Over one projector, in the New York showing, was placed a 
Polaroid screen that polarized its light in a vertical direction, 
while light from the other was similarly polarized in a hori- 
zontal manner. Members of the audience were provided with 
"glasses" made of the polarizing film and oriented in the same 
way. When these spectacles were used to watch the film, each 
eye saw only the proper picture, and it appeared solidly in 
three dimensions. 

Still better is a system that would give similar results with- 
out having the audience bother to hold special viewing glasses 
before their eyes. Dr. Herbert E. Ives, physicist of the Bell 
Telephone Laboratories, son of Frederic E. Ives, the color 
photography pioneer, devised a means of doing this. The 
picture was taken with a battery of cameras, showing the view 
from a number of angles, and projected, from the same number 
of projectors, from behind the screen as in the Translux 
Theaters. Between screen and audience were a series of vertical 
glass rods which acted as lenses but bent the light rays in a 
horizontal direction only. They sent to each eye the proper view. 
This process gave an image which actually appeared solid; that 
is, one could move the head from side to side, and see around 
the objects depicted. 

The complexity of the process has hampered its application, 
although a couple of years ago reports reached the United 
States that a theater using this idea had been opened in 
Moscow. Full details of the process, however, never reached us 
though it was said to be extremely effective, as well it might 
be. A special production was made to demonstrate its ad- 
vantages. One scene showed apple blossoms falling from a 
tree, and it was said that they seemed to be descending into 
the audience. 

Perhaps this will be the picture of the future. Then pho- 
tography will have obtained well-nigh perfect realism. Edison's 
dream of a performance in the Metropolitan Opera House, ap- 
pearing exactly like the original, though with actors long since 
dead, may thus be achieved. 

XVIII. New Sounds in the Theater 

A few years ago an audience in Constitution Hall in 
Washington heard one of the strangest symphony concerts on 
record. The music was by the Philadelphia Orchestra. Each 
instrument was heard in its proper place on the stage right, 
left, forward or rear. Everything was perfectly natural except 
that there was no orchestra! Yet this was no recorded concert; 
at the very moment the orchestra was actually playing, but in 
its home auditorium, the Academy of Music in Philadelphia. 

This was the first demonstration of the Bell Telephone Labo- 
ratories* system of "stereophonic" transmission of sound. Three 
microphones were placed at strategic points among the musi- 
cians, and each, through its own wire channel, fed a loud- 
speaker in a corresponding position on the Washington stage. 
Thus, for the listeners, the particular combination of volume 
from the three speakers for each instrument gave the effect of 
sound coming from some particular position on the stage. 
Other demonstrations of stereophonic possibilities were given. 
A stage hand called for a hammer, an assistant slid it across 
stage to him. In Washington it was possible to hear the two 
men, one on one side, the second on the other, and also to 
follow the hammer on its journey taking place more than a 
hundred miles away. 

To give even greater flexibility to the effects produced than 
would have been possible with the orchestra alone, Leopold 
Stokowski, the orchestra's director, sat in a box in the Wash- 
ington hall, manipulating controls for the speakers. In this way 
he could effect a range in volume much greater than anything 
the orchestra could accomplish directly. For example, with all 
instruments playing, the intensity could be reduced to a 
pianissimo softer than that of a single muted violin. Or 



crescendi could be developed to a fortissimo greater than the 
musicians themselves could ever produce. 

In later demonstrations the scientists of the Bell Laboratories 
produced the same effects in recorded concerts. The sounds 
from each microphone are recorded on film as with sound 
movies. The film, instead of a single sound track, has three, and 
also another control track which regulates the output of the 

Something comparable was devised for the first presentations 
of Walt Disney's cartoon feature picture Fantasia, with the aid 
of Radio Corporation of America engineers. Mr Disney is said 
to have had the idea first when, several years ago, he watched 
a bee buzz off the screen in one of his own cartoons. The 
finality of the disappearance bothered him and he felt that it 
should have been possible to have the bee around even if it 
were not required on the screen. 

About this time a Mickey Mouse short, based on the ballad 
by Goethe which in turn had inspired Paul Dukas' music The 
Sorcerer's Apprentice, was being made in the Disney studios. 
The music was to be conducted by Stokowski. As it progressed, 
it became more elaborate, finally being expanded into a full- 
length feature, and with other musical numbers added. The 
recording of the music was done in the Academy of Music in 
Philadelphia, by the Philadelphia Orchestra under Stokowski's 

An RCA statement described as follows the technique: 

For every group of loudspeakers used in the theater there had to 
be a separate source of sound synchronized with the picture. So when 
Mickey Mouse appears on the right, a control mechanism switches 
on the loudspeaker directly behind him and veers the sound to an- 
other speaker when he moves. 

Stokowski directed as he would ordinarily, and the orchestra played 
with its familiar fire and skill But there all convention ended. For 
the music had to be divided up in such a way that later it could be 
blended at will and reproduced through the required loudspeaker 
wherever Disney wanted it. 

To do this, the orchestra was divided into five sections strings, 


basses, woodwinds, brasses and percussions. Each section was 
covered by three microphones and recoided on a separate track. Also, 
there were three additional straight recordings, two on film, one on 
records, and a beat track giving the beat, entrance cues, etc., which 
the cartoonists used to synchronize the action to the music. Each of 
these tracks could be blended in any way with any other track or 
combination of tracks, so that actually any single instrument, section 
or the whole orchestra could be heard coming from any one point on 
the screen. 

It worked like this: During a recording, the music approaches a 
clarinet solo. The Disney engineer, sharing the podium with Sto- 
kowski, signals the engineer in charge of the woodwind section to 
look out for the clarinet, and gives him the level at which it is to be 
recorded. In the final blend, the clarinet's loudness is played up or 
played down depending upon what purpose it fulfills in the finished 
production. And it may be heard in the theater from any desired 

The Bell Laboratories' stereophonic sound, and the RCA 
"Fantasound," as the system used for Fantasia was dubbed, are 
both adaptations of the electronic tubes described earlier in 
this book. But both involved a significant departure from most 
other uses of these devices in connection with public per- 
formances. The usual public-address system, with its micro- 
phone, amplifier and loud speaker, is used to overcome short- 
comings either of the auditorium or of the speaker himself. 
If he had a voice sufficiently powerful, or if the acoustics of 
the room were good enough, in most cases such a system would 
not be needed. Stereophonic sound and Fantasound did more 
than this they actually made possible effects that could not 
otherwise have been obtained. 

The most important research program in this field, however, 
is one that has been conducted since 1930 by Harold Burris- 
Meyer and his associates at Stevens Institute of Technology in 
Hoboken, N.J. Many musicians and theatrical people have co- 


operated, while funds have been furnished by the Rockefeller 
Foundation and the Research Corporation. Part of the work has 
been done at the Metropolitan Opera House, though early in 
1942 it was necessary to remove the equipment to use it on a 
war problem, and plans for using the system in the perform- 
ance of various operas had to be postponed. 

In a WGY Science Forum radio talk, Mr. Burris-Meyer said: 

Most sound controlling devices have been mechanical. The human 
voice is a mechanical gadget. And all the conventional musical instru- 
ments are pounded or blown or scraped to make them work. And, 
satisfactory as they are the tympanum, the pipe organ and the 
human voice they never quite make or control the sound as com- 
pletely as the composer would like to control it. The flute can only 
play so softly and still operate If you want a softer note, it has to be 
played by a stringed instrument. The violin can only play so loud, 
the voice can only sing so high, and no mechanical sound source 
makes the sound come from any place except where the instrument 
is. It doesn't take much artistic imagination to see that if you can 
make the music come from wherever you want it to, your artistic 
scope is a good deal greater than if the music comes from a place 
which you can't help. 

Also, it is artistically advantageous to have a dynamic range, that 
is, the distance between soft and loud, which is considerably greater 
than any mechanical instrument can make; and it is nice to have the 
sound come from far away or near at hand if that is required. Now 
the musicians did almost all that was possible to control their medium 
by mechanical means some time ago, and they were pretty badly 
stymied when electronic devices came along. 

By electronic means it is possible to make the sound do anything 
the artist wants it to do. It is possible to make it come from where you 
want it to; the Angels' Chorus in Faust can come from the chandelier; 
Ariel in the Tempest can move about unseen above the audience; the 
celestial orchestra in Sidney Howard's Madam, Will You Walk? 
can fill the whole theater. The sound can be made as loud or soft as 
is requisite. The flute can play music normally assigned to a muted 
violin; the shout of the crowd in Elijah can rattle windows across the 
street. The theater can have any reverberation characteristics which 
seem appropriate to the sound The church scene in Faust can sound 
as reverberant as is appropriate to a church; the scene in the garden 
can sound as non-reverberant as is appropriate to a garden. 


That is, in addition to the very complete control of lights and 
mechanical features available for dramatic producers, complete 
control of sound also is now possible. This does not mean 
merely the familiar sound effects of thunder, rain, airplane 
motors, or pounding hoofs. Those can be produced too; but Mr. 
Burris-Meyer objects very strenuously to calling his work 
"sound effects.'' He feels that the entire auditory component of 
a show should have enough unity and dramatic significance to 
form a complete work of art by itself. 

In the spring of 1941, at the Stevens Theater, he presented 
the Second Sound Show. The first had been given seven years 
earlier, and both were intended to demonstrate the progress of 
that research. The show consisted of excerpts from various 
plays which brought out the effective use of sound-control 
methods. One was Shakespeare's The Tempest, a play most 
difficult to present if any effort is made to follow the implied 
directions. "The isle," on which the action is laid, says Caliban 
in Act III, 

. . . is full of noises, 

Sounds and sweet airs, that give delight and hurt not. 
Sometimes a thousand twangling instruments 
Will hum about mine ears; and sometimes voices. 

An important character is Ariel, the "airy spirit," who 
appears, generally invisible, and departs 

. . . to fly, 

To swim, to dive into the fire, to ride 

On the curl'd clouds. 

Surely the illusion is given a severe jolt when, in such a 
part, appears a human being of flesh and blood, obviouslv just 
as corporeal as the other characters or any of the audience. He 
hardly obeys Prosperous injunction: 

. . . be subject 

To no sight but thine and mine; invisible 

To every eyeball else. 


In the Stevens production, on the other hand, we saw what 
Shakespeare must have had in mind as an unapproachable 
ideal when he created the part. Prospero is on an apparently 
empty stage, conversing with Ariel, whose voice comes from 
the other side. While the conversation continues Ariel, as we 
might expect, flits around the theater. His voice comes from the 
rear, then from above apparently he is flying about over the 
heads of the audience. And the source of the music from his 
pipe and tabor moves about with him. 

Another scene was from A Midsummer Night's Dream the 
one in which Titania, the fairy queen, temporarily bewitched 
by her husband, Oberon, falls passionately in love with Bottom, 
who then has the head of an ass. Before and after this Bottom 
speaks with his own voice. But when he has the head his voice, 
though understandable and still resembling his normal voice, 
has the quality of an ass's bray. 

This involves two techniques. First, there is the remaking 
and recording of the actor's speech. (The sounds made by a 
jackass of the four-legged variety have a much greater range 
of pitch than the human voice.) Then, when the recording 
was played, the control of perspective was used, shifting from 
one loudspeaker to another as Bottom moved about the stage, 
so that throughout he seemed to be the source. This control of 
auditory perspective was also used to make the source of Ariel's 
voice move about the theater. 

Remaking the voice was accomplished with a device called 
the Vocoder, which was developed by Bell Laboratories' 
engineers. It was the ancestor of the Voder, the device for 
making synthetic speech that was demonstrated at the New 
York and San Francisco World's Fairs. With the Vocoder, the 
human voice may be made to modulate any sound that can be 
brought into the studio: the sound can be remade to have any 
desired pitch or quality, or any range of pitch. A waterfall, 
thunder, an explosion, a sound of falling bricks, all can be made 
to talk. Somewhat similar in effect is the Sonovox of Gilbert 
Wright, used in the Disney studios. This transmits any de- 


sired sound to the throat of a person who can talk or sing, 
the transmitted sound serving as a substitute for the sound that 
would normally be produced by the singer's larynx. (This 
made it possible for the locomotive to sing its song in Dumbo. ) 
And still a third device is one which is due to Professor F. A. 
Firestone of the University of Michigan. Through a glass tube 
a sound is piped to the base of the performer's tongue, where 
it can be used as a source of song or speech. One person, with- 
out using his vocal cords, can sing an octet with this apparatus! 

One of the most effective uses of the remade voice in the 
Second Sound Show at Stevens was the opening scene in 
Macbeth. Mr. Burris-Meyer explained, in his WGY talk, that 
they wanted "to see if the witches could be made into 
twentieth-century demons which are visible only to Macbeth, 
but cast shadows as they move about the fire, which the 
audience can see. Three pleasant voices were rebuilt so that 
their owners would never know them. One was made higher 
than the human voice can go, one was given a quality which 
is a cross between a rock-crusher and a whiskey baritone, and 
the third was transformed into a basso. For the production, the 
dialogue was played against a background of the scherzo of 
ProkofiefFs Concerto in D Major for violin and orchestra." The 
results were most successful. 

This was the sequel to an earlier accomplishment. "Back in 
1934," said Mr. Burris-Meyer, "we set out to make the Ghost in 
Hamlet sound like a ghost. So we built a voice which was 
pretty sepulchral and dubbed it on to an ectoplasmic figure, 
and made quite an impression. The technique of making the 
voice consisted in suppressing some of the voice frequencies 
and emphasizing others. It wasn't long until the same idea 
adapted to radio as a sort of juke-box voice became part of 
the standard radio bag of tricks. The voice of the Ghost came 
from a translucent figure moving about the stage." 

Reverberation is one of the most important qualities in 
which halls differ acoustically, and means have been devised 
for its control. The Stevens Theater is the assembly hall of an 


old building, with very little of the qualities of a great cathe- 
dral. Yet in the church scene from Gounod's Faust, where 
Mephistopheles summons Marguerite, reverberation, with its 
relative the echo, was introduced., expecially in the case of the 
Mephistophelian voice. And in another demonstration of re- 
verberation control, a special recording of the Toccata in F 
from Widor's Fifth Organ Symphony was played with the re- 
verberation characteristics of the Church of St. Sulpice in Paris, 
where the composer was organist. 

This is achieved with a modern form of a device called 
the telegraphone, invented some years ago by Professor V. 
Poulsen of Copenhagen. Sound was recorded by magnetizing 
parts of a long wire, and reproduced with a device in which the 
magnetism of the wire as it rolled through controlled the 
motion of a diaphragm. Now this is made better with electronic 
tubes, and great faithfulness of reproduction is obtained. The 
advantage is that by passing the wire through a strong, con- 
stant, magnetic field, the old record is wiped off and the wire 
is then ready to receive a new one. For reverberation effects, an 
endless wire is run through the machine. The sounds are re- 
corded and played back once or several times, a fraction of a 
second apart, and fed into the circuit along with the impulses 
from the original sounds. The interval between the repetitions, 
the number of times they are heard, and the decrease in volume 
in each are all factors that may be varied, so as to reproduce 
the reverberation of any desired building, real or imaginary. 

One of the first things the Stevens experimenters found was 
that the sound intensity affects the posture of the audience. 
They can be made to sit up straight, to move forward, or to 
relax, merely by varying the volume. 

"With present-day audiences hardened by much theater- 
going," Mr. Burris-Meyer has said, "an emotional response to a 
dramatic episode must be strong indeed if it is to be physiologi- 
cally observable or measurable. Any device by which it is 
possible to achieve an obviously strong emotional response may 
constitute a powerful tool for the artist in the theater/' 


However, as he later found, the sound does not actually need 
to reach extremely high intensity in order to produce the im- 
pression of great loudness. All you have to do is to shake the 
building itself, mechanically, from a direction different from 
that in which the sound is actually coming. A very loud sound 
does shake the building; therefore if yo* 1 shake the building 
when any sound is made, the audience thinks it is loud even if 
it isn't! 

Experiments were also made with changes in frequency; that 
is, in the pitch or "shrillness" of the sounds. One remarkable 
effort was in a play by Elmer Rice, called Adding Machine, in 
the "brainstorm" scene. "We tried to achieve expressionism in 
sound, in conformity with the idiom of the play," Mr. Burris- 
Meyer later explained, "and drive the audience crazy as the 
principal character lost his reason. We almost did. And the 
principal device was an almost pure tone warbled and raised in 
frequency and intensity for about thirty-two seconds while the 
stage spun around and Mr. Zero turned killer. The Adding 
Machine episode showed that you could use control of fre- 
quency very simply to achieve the dramatic objective of the 

Many types of equipment are used in this work. Some are 
standard devices which have been adopted and adapted. 
Others are units particularly designed and built. There are 
loudspeakers and microphones galore; there are electrical con- 
trols which can regulate the speakers through which sounds 
from particular microphones are produced, and to permit 
gradual fading from one to another. There are the devices for 
recording sound on disc, film and magnetized wire. And there 
are other novel sound-producing devices which feed into the 

One of the most versatile is a "thunder screen." It is a square 
frame of wood to which a copper fly screen is attached. To the 
center is fastened a pick-up like that of a microphone. Rubbing 
or tapping the screen energizes the pick-up and produces a 
variety of sounds, which of course can be remade with the rest 


of the sound equipment. Sometimes the screen is stroked with 
a cloth. Again it may be hit with a stick, or perhaps touched 
lightly with a small brush. It will make a realistic airplane, 
which, with proper control, seems to be circling around the ceil- 
ing, then flies off in the distance over the stage. 

In a scene in the Second Sound Show, from Eugene O'NeilTs 
The Emperor Jones, the thunder screen was used as the jungle 
drum that throughout this impressive play, is heard in the back- 
ground gradually getting louder. In this production it started 
with very low notes, so deep that they could be felt rather than 
heard. This established the cadence before the actual sound 
was noticeable. The effect of this varied. Some said they did 
not notice it, while others were conscious of the beats from the 
start. One actor who played the part of Smithers claimed not to 
notice it, but it was observed that he gave his lines in cadence 
with the beats whereas in an ordinary production he showed 
no such rhythm. 

Among the many artists who have co-operated with Mr. 
Burris-Meyer in his work is Paul Robeson, distinguished bari- 
tone. With him a technique was developed which he has 
employed regularly in recitals, while others have used it too. 
Unlike the other parts of the Stevens researches, this is for the 
benefit of the artist rather than for the audience, though they 
benefit indirectly as they enjoy a concert more the better the 
artist does it. Singers have often noticed that they sound better 
to their own ears when singing in the bathroom than on the 
concert stage. The reason, naturally, is that the hard walls of 
the small room give high reverberation, and they actually hear 
themselves. In a large hall the voice is lost, and singers cannot 
form a good idea of the way they really sound. 

The Robeson technique uses a concealed microphone with a 
loudspeaker just off-stage. This is highly directional; that is, it 
can only be heard in the direction toward which it is pointed. 
It is aimed at the artist, so that he can hear himself as if he 
were singing in his shower, but the audience is unaware of the 
loudspeaker and hears only the direct sounds. Because of its 


synthetic character, Mr. Robeson dubs the outfit "Synthea." 
Somewhat comparable was an installation tried out in the 
Metropolitan Opera House to enable the performers in the up- 
stage areas to hear the orchestra as well as the audience does. 

With Mr. Burris-Meyer, and the equipment that he used, 
serving in a war job, it became unlikely that there would be 
any further development of his methods for the present. For 
the future, he has said: 

It means that speech, prop sounds, background music, all the sound 
in the show, if planned according to the principles of musical com- 
position, can have many times the dramatic power they now have. 
We have made a number of experiments to test the theory. They have 
been exciting. A production in which the whole auditory component 
is composed as music has all the advantage of opera minus the heavy 
soprano or the limitations of the human voice or the musical instru- 
ment. As a result the limitations on the auditory component of the 
show are off. The players may speak with the tongues of men and of 
angels. With sound you can compel the audience to laugh, to weep. 
You can knock them off their seats, you can lay them in the aisles, 
you can make them believe what you will. It has been done. One day 
we shall see the production of The Tempest Shakespeare envisioned, 
and a Gotterdammerung which would have satisfied Wagner. 

XIX. Into the Atom 

A new kind of chemistry has been born in recent years. It is a 
kind of chemistry which sometime may well make our present- 
day chemistry the sort of processes described in previous 
chapters, of rearranging molecules and atoms to make gasoline, 
rubber, explosives seem quite old fashioned. This chemistry 
penetrates to the heart of the atom. It has realized the ancient 
dream of the alchemists, a dream which chemists of the nine- 
teenth century thought hopeless. 

Whereas the alchemists failed to change lead or some other 
"base" metal into gold, modern science has done it in fact, 
has changed many elements into others. The fact that the cost 
of making the change far exceeds the value of the elements you 
get in no way detracts from the significance of the achieve- 
ment. As this modern alchemy develops, as we learn more 
about its principles, its value to mankind will be infinitely 
greater than merely making lead into gold with some mystic 
"philosopher's stone." 

The word "atom" means something which cannot be divided, 
and that was the past century's conception of it; the atom was 
the fundamental particle. There were a number of different 
kinds, one for each element. There could be no such thing as 
"atomic structure," for how could a particle incapable of sub- 
division have any structure? An atom of hydrogen, of sodium, 
of any element, was thought to be always the same. In chemical 
reactions you might shift the atoms around, making new mole- 
cules. You might take a sodium atom away from the atoms 
of hydrogen and oxygen with which it is associated in caustic 
soda, hitch it on to a chlorine atom taken from a union with 
hydrogen in hydrochloric acid. The new pair, sodium and 
chlorine, is common salt. But in this process the atoms have not 
changed they are the same throughout. 



Experiments such as those of J. J. Thomson, however, which 
revealed the existence of the electron, showed that the atom is 
a complicated thing at least as much so as a grand piano, be- 
cause it is capable of giving out various "notes," which show up 
as light of different colors or wavelengths. 

The modern idea of the atom goes back to the theory pro- 
posed in 1913 by Niels Bohr, a Danish physicist then working 
with Sir Ernest Rutherford at Cambridge University. We can 
illustrate his concept with the simplest atom, that of hydrogen. 
There is a nucleus, consisting of a unit charge of positive 
electricity, and revolving around this a negative unit charge, or 
an electron. Normally, the electron moves in an elliptical orbit 
around the nucleus, like a planet around the sun. However, 
there are other possible orbits, farther out from the nucleus, in 
which the electron can be made to move when energy is 
applied to it. But then it tends spontaneously to return to its 
favorite orbit, and as it does so it gives out the energy again 
as a burst of radiation, or light either visible or invisible. There 
are a number of possible jumps that the electron may make, 
and each shows a characteristic note, or wavelength. Other 
atoms are more complicated, with more electrons and more 
orbits, so they have more possible jumps, and more lines in 
their spectrum, in many cases. 

Nowadays physicists no longer picture the electrons as little 
planets revolving around in nice, precise orbits. Rather have 
the orbits themselves become rather hazy regions in which, 
probably, the electron will be found, while the electron is not a 
definite entity either, but a sort of waviness. 

However, the atom has been shown to be a complicated 
thing. We might compare it with a watch, a complex assem- 
blage of mechanism surrounded by a metal case. The atom 
does not have the metal case, but it does have a shell, made up 
by the field of force which surrounds it. Ordinary chemistry 
does not penetrate this shell, but our new chemistry does it 
gets into die heart, or nucleus, of the atom. 

(see page 274) 

(see page 224) 

(see page 236) 


r .* 





(see page 258) 

(see page 259) 

(see page 272) 


(see page 265) 


The physicists' most powerful artillery was needed to get 
through the shell, and reach the nucleus. "Artillery" is used 
advisedly, for the process actually consists of firing bullets at 
the atom; not ordinary bullets, but bullets which are pieces of 
atoms themselves, of a size comparable with the atoms to be 
smashed. The first to be used were those constantly given off 
by radium; nuclei of helium atoms, also called "alpha particles." 
These have energies high enough to penetrate the forces 
around the nucleus, provided you aim them right. 

Since you cannot see either the atoms you are trying to hit or 
the bullets with which you are shooting, aiming is out of the 
question. But if you are in a dark cellar in which a swarm of 
bats is flying, and you have a machine gun which you spray 
around, you will occasionally hit a bat. This is in effect what 
Sir Ernest Rutherford did at Cambridge University in 1919, 
when he accomplished the first actual transmutation of one 
element into another and realized the alchemist's dream. 

His apparatus was a box containing nitrogen gas. Inside was 
a bit of radium, the machine gun, while the nitrogen atoms 
were the bats. At one end of the box was a "window" of thin 
silver. Outside this window was a screen of zinc sulfide, a 
material which glows with momentary starlike points of light 
every time an alpha particle strikes. But no particles struck it, for 
the silver window was just too thick to let them pass. 

Occasionally a spark of light did appear on the screen! Here 
was a particle that came from the box with more energy than 
an alpha particle. Rutherford studied these new particles in 
various ways by measuring the effect on them, for example, 
of a magnet and established that they were nuclei of hy- 
drogen atoms, or what soon came to be called protons. What 
had happened was that an alpha particle had squarely hit the 
nucleus of a nitrogen atom, and had, indeed, been captured by 
it. A proton had been given off. But the alpha particle itself 
consists of two charges two protons. Hence the nitrogen 
nucleus had one more proton than before it had eight instead 


of the seven which it normally carried. However, the element 
with eight protons in the nucleus is not nitrogen it is oxygen! 
Not ordinary oxygen, but a form in which the nucleus is one 
unit heavier than the ordinary kind. 

Most of the elements have been found to exist in these 
several different weights, and the separate forms are called 
"isotopes." Ordinary oxygen, which makes up a fifth of the air, 
contains 99.76 per cent of an isotope of weight 16, a very small 
amount of weight 17 ( the kind that Rutherford produced ) and 
a fifth of a per cent of weight 18 as well. But the transmuted 
nucleus of heavy oxygen contained not only one more proton 
than the nitrogen nucleus from which it was produced: the 
alpha particle also left two neutrons. These are particles that 
another Cambridge scientist, James Chadwick, had discovered 
in 1932. With the same mass as the proton, but having no elec- 
trical charge, the neutron fitted very conveniently into concepts 
of atomic changes. 

It explained, for example, why two isotopes can have differ- 
ent weights yet be the same element. The number of protons 
in the nucleus ( the same as the number of electrons in an ele- 
ment in its normal state ) determines what the element is. Thus, 
all nitrogen atoms have seven protons, and all oxygen atoms 
have eight. Ordinary oxygen has in addition eight neutrons, but 
its heavy isotopes have either nine (for weight 17) or (to make 
weight 18) ten. 

There is also a heavy form of hydrogen, called "deuterium," 
which Dr. Harold C. Urey of Columbia University discovered 
in 1932. Ordinary hydrogen contains it in the proportion of 
about one part in five thousand, but it can be separated into a 
nearly pure state. Its nuclei, called "deuterons," have proved 
the most effective atom-smashing bullets thus far. 

A deuteron consists of a proton, like the nucleus of ordinary 
hydrogen, plus a neutron, making it twice as heavy. Because it 
has a single charge, it is just as easily fired by electrical forces 
at the nucleus as is the solitary proton. And when it gets close 
to the nucleus of the atom under attack, the neutron is released 


and sent in to perform its mission. However, neutrons by them- 
selves, and also protons, unaccompanied, are used as atomic 
bullets as well. 

Protons were the projectiles which Cockroft and Walton 
used in 1932, speeding them up with energy equivalent to 
700,000 volts and aiming them at lithium. Nuclei of helium 
atoms alpha particles were given off. This was actually the 
first success at atom-smashing with laboratory apparatus, since 
the alpha particles that Rutherford had used were produced 
by natural processes taking place in the radium, and not under 
the control of man. 

To advance further required the use of more energetic par- 
ticles. Higher voltages were needed to send the bullets on their 
way. Two machines have been used to do this. One is the Van 
de Graaff generator. Essentially, this generates electricity in the 
same way that you may generate it on a winter day, when you 
scuff your feet on a rug and draw a spark from a light fixture 
or some unsuspecting person's ear. In rubbing over the rug, 
you accumulate an electrical charge. The central part of the 
Van de Graaff machine is an endless belt of insulating material 
on to which an electrical charge is sprayed. The upper end of 
the belt is inside a hollow metal sphere, and its motion carries 
the charges to this sphere. There they are drawn off; the sphere 
itself accumulates the charge, while the belt goes down again 
for more. When the charge is great enough, it can overcome the 
natural resistance of the air; and a spark jumps to near-by 
grounded metal. By enclosing the entire apparatus in a tank, 
with gas under pressure, the resistance is increased and higher 
voltages up to 5,000,000 volts may be obtained. Then these 
voltages may be used to accelerate positive or negative par- 
ticles for atom-smashing experiments. Several of these Van de 
Graaff generators have been installed in great research labora- 


The other and even more popular atom-smashing weapon is 
the cyclotron, invention of Dr. Ernest O. Lawrence of the Uni- 
versity of California. It reaches higher voltages, but thev can- 
not be as accurately controlled. We can think of it as a sort of 
atomic sling-shot the kind that David used to slay Goliath, 
when he whirled a stone around his head in a sling, then let 
it fly when it had gained sufficient speed. 

In the chapter on electrons we saw how Dr. W. D. Coolidge 
cascaded electrons to speed them to high energies. By applying 
voltages of perhaps one hundred thousand several times in suc- 
cessive steps, the particles were given successive boosts and 
attained energies equaling the sum of these steps. With a de- 
vice called the linear accelerator the same thing can be done 
with protons, and this device has been widely used in atom- 
smashing experiments. In fact, in 1931 Lawrence himself, then 
thirty years of age, speeded particles to a million and a quarter 

But the linear accelerator gets longer and longer as its power 
is increased, and this imposes a limit beyond which it is too un- 
wieldy to use. 

Then Lawrence turned to the sling-shot idea. The cyclotron 
was the result, winning for him the Nobel Prize in Physics in 
1939, the last given. Electrons from a hot filament hit molecules 
of a gas, such as hydrogen; and protons (or deuterons if the 
gas is heavy hydrogen) are formed inside a chamber that is 
well evacuated, for very little gas is needed to supply the bul- 
lets. Also in this vacuum chamber are two hollow D-shaped 
electrodes, called "dees." Cut a pill box into two semicircular 
halves, separate the halves slightly, and you have a good model 
of these dees. 

The dees are connected to, essentially, a powerful short-wave 
radio transmitter, giving a rapidly oscillating electrical current. 
Each dee is continually changing from negative to positive, 
then back again, many times per second, and the two dees are 
always oppositely charged. Our proton, then, knocked out of a 
hydrogen atom by an electron, has a positive charge; it is at- 


tracted to the negative dee. Since the entire vacuum chamber 
is between the poles of a powerful magnet, the magnetic field 
causes the proton to move in a semicircle, back to the opening 
between the dees. By this time their charges are reversed; now 
the other has the negative charge, so the proton is yanked across 
the opening with an increase in speed. 

Again it moves in a semicircle, under the magnetic influ- 
ence; again it comes to the gap, again the field has changed. 
Now the first dee is again negative, so the proton has another 
jerk. It goes around and around, moving in ever-widening cir- 
cles accelerating each time it crosses the space between the 
dees. Compared with the linear accelerator, the voltage used 
in any one jump is small; in some of Lawrence's early experi- 
ments it was only about four thousand. 

Finally our proton is traveling around the edge of one dee, 
then it comes within reach of a negatively charged plate which 
pulls it out of the dees entirely. It passes easily through a thin 
metal window, out into the open air where it can be used to 
bombard anything that happens to be in range. What happens 
to one proton ( or deuteron ) is, of course, happening to a swarm, 
and they all emerge as a potent beam. 

The first cyclotron was only four inches in diameter, and a 
small magnet sufficed. But to increase the power, bigger and 
bigger magnets had to be used. At the University of California's 
Radiation Laboratory in Berkeley, of which Lawrence is di- 
rector, a sixty-inch machine, with a 220-ton magnet, speeds the 
particles to energies of around 16,000,000 volts. More than 
thirty other cyclotrons are in regular use in research labora- 
tories throughout the world; and Lawrence and his colleagues 
have in an advanced state of construction, on a Berkelev hill 
overlooking San Francisco Bay and the Golden Gate, the big- 
gest of all. The huge electro-magnet is made of 4900 tons of 
steel; the beam of atomic projectiles will be so powerful that 
it will penetrate, it is expected, about 140 feet of air. The 
voltage will be between 100 and 300 million. 

When this cyclotron goes into operation many now formida- 


ble barriers to science's insight into the atom will undoubtedly 
be broken down. As the protons, deuterons, or even nuclei of 
helium atoms are spun around, some of them stray from the 
main beam, hit the copper walls of the chamber, knock neu- 
trons out of the copper atoms, to be strewn around promiscu- 
ously. A cyclotron therefore is usually surrounded by tanks of 
water several feet thick, which form barriers to the wandering 

All of the effects of neutrons on the human body are not 
known, though they seem to have some. (Experiments have 
shown that they produce sterility in mice about four times as 
effectively as X-rays.) When in use, therefore, the cyclotron is 
controlled remotely from a neighboring room. 

But often neutrons are desired for use in experiments. Then 
they are produced by bombarding lithium, beryllium, or some 
similar light metal with the deuterons. It was in this way, for 
example, that two Harvard University physicists, according to 
their report in 1941 to the American Physical Society, realized 
the dream of the alchemists; for mercury was turned into gold. 
The physicists are Dr. Rubby Sherr and Dr. Kenneth T. Bain- 
bridge. No vast fortunes awaited them as a result, however, 
for the amounts of gold produced were so insignificant that an 
indirect means of detecting it had to be resorted to. Also, the 
gold was in the form of isotopes which quickly decayed 
into other elements, some in a few minutes, others in several 

The method Sherr and Bainbridge used shows some of the 
ingenious tricks that science must employ in these researches. 
Deuterons from the Harvard cyclotron were fired at lithium, 
neutrons were obtained and, in turn, used to bombard mercury. 
Then a small bit of gold was mixed with the mercury and the 
mercury was boiled away, leaving the gold by itself again, 
except for minute amounts of platinum, which had also been 
formed by transmutation from the mercury. This was removed 
by a chemical process. When the gold was tested, it was found 
that it contained several new forms which behaved like radium, 


spontaneously disintegrating and giving off certain kinds of 
radiation in the process. 

Very delicate tests can be made for these radioactive atoms, 
tests far more sensitive than ordinary chemical procedures. 
Since the gold itself had not been exposed to the neutron beam, 
it was evident that the radioactive forms must have come from 
the mercury. Yet there was so little of it that tests of the mer- 
cury for gold, after the exposure had been made, would have 
yielded no results. But when new gold was put in, it acted as 
bait to draw the transmuted gold into union with it; and then 
the original gold and the transmuted gold could be extracted 
together. 1 

It is in making radioactive elements artificially, however, that 
the cyclotron has had one of its most important applications. 
In fact, some have been erected with this main purpose rather 
than for use primarily in research into the atomic nucleus. Ra- 
dium, and all the substances like it, that we call "radioactive/* 
show a characteristic disintegration into other elements, with 
the liberation of one of three types of ray as they do so. In the 
case of radium the disintegration proceeds at such a rate that, 
after 1690 years, half of the original amount will be gone; at 
the end of another 1690 years, half of that will have disin- 
tegrated, and so on. This 1690-year period is said to be the 
"half-life" of radium. Some radioactive substances have much 
longer half-lives, while others, including most of those made 
artificially, are much shorter, some being measured in small 
fractions of a second. 

Radioactive phosphorus, which is made when you expose or- 
dinary phosphorus to the beam of a cyclotron, has a half-life 
of fourteen days, which is a very convenient length of time. It 

1 Ordinary gold may be made, too, but platinum is needed as the raw material. 
Since that is more valuable than gold, this process would have held little appeal 
for the alchemists. But if you fire a neutron at ordinary platinum a heavier form 
is created, which is not stable. It decomposes into ordinary gold, with the emis- 
sion of an electron, and a burst of energy. 


can be injected into the body, where it performs its mission; 
yet after that its activity dies away. If you were to inject radium 
into the body, it would keep up its activity long after it was 
needed for therapy, and would then do considerable harm. 
These radioactive elements behave chemically just like the 
same elements in the customary form, and in the body they be- 
have the same way too. The phosphorus is deposited in the 
bones, and that makes the radioactive form effective for treat- 
ing leukemia, a disease in which the white blood cells, neces- 
sary in moderate amounts for combating infection, run away 
and overproduce. These cells originate in the bone marrow, 
so, when the radioactive phosphorus is deposited in the bones, 
it is just where it is needed for the greatest effect. 

Another important use of artificially radioactive elements is 
as "tracers." Botanists, for example, have found them useful in 
studying the physiology of plants. Suppose that you want to 
trace the path of phosphorus through a plant's anatomy. Phos- 
phorus goes in at one place, and is later found elsewhere; but 
how can you be sure that these are the same atoms? By making 
them radioactive, the atoms can be tagged. That is, radioactive 
phosphorus is formed, and mixed with the plant's nutriment. 
As the radioactive atoms reach various leaves, for example, they 
can be detected. The beta rays, really electrons, which they 
give off, will write their autograph on a photographic plate. Or 
another form of detector, called the Geiger counter, will re- 
veal their presence by flashes of an electric lamp connected to 
it, or by clicks in a loud speaker. Similarly, radioactive tracers 
can be fed to animals, in studying the operation of their bodies. 2 

Radioactivity can be induced in other ways than with the 
cyclotron. In fact, it was first accomplished with a natural 
source, and there is a most appropriate family connection here. 

2 Nearly all of the 92 elements have been made radioactive, some in several 
forms, so that there are more than 350 radioactive isotopes which have been re- 
ported since this work began in 1933. 


Madame Marie Curie, and her husband, Pierre, discovered 
radium in 1898. It was in 1933 that their daughter Irene and 
her husband, Frederick Joliot, discovered artificial radioactivity; 
and they used the rays from polonium ( one of the other radium 
elements which Marie Curie had also discovered) to provide 
the rays. When they employed alpha rays from polonium to 
bombard a piece of aluminum, it gave off other rays which 
proved to be positrons particles like the electron, but carry- 
ing a positive charge. Even after the bombardment was ter- 
minated, the aluminum continued its radiation, and this gradu- 
ally weakened, in the same manner as the rays from natural 
radium gradually weaken. 

Then Enrico Fermi, an Italian physicist who is now at Co- 
lumbia University, one of the galaxy of brilliant scientists that 
America has secured as a result of Axis shortsightedness, 
showed the effect of slow neutrons. He made neutrons by shoot- 
ing alpha particles at beryllium powder; but these directly did 
not have an effect. However, when he passed his neutrons 
through a substance such as paraffin and reduced their speed, 
they became much more effective. This seems contradictory, 
but it has a reasonable explanation. When the bullets tear past 
the atomic nucleus at full speed, they are there such a short 
time that they have little opportunity to be influenced, and they 
continue in an uninterrupted path. But when they are moving 
slowly, there is more time in which the attraction of the nucleus 
can pull the neutron in to do its work. 

Electrons also can cause elements to become radioactive. 
This has been shown in the General Electric Research Labora- 
tory with a device known as the induction electron accelerator, 
in which, with electrons speeded to energies of 20,000,000 volts, 
copper has been transmuted to a radioactive form. 3 

3 The electron accelerator, was developed by Dr. Donald W. Kerst, of the 
University of Illinois, who came to the General Electric Laboratory for a year 
and a half to work on the device. The 20,000,000-volt equipment, after it was 
used for preliminary experiments at Schenectady, is now at the University of 
Illinois, while the G. E. scientists are completing a still larger one, capable of 
speeding electrons to 100,000,000 volts. 


The operation of this device is suggestive of the cyclotron, 
for it also speeds its atomic bullets in a spiral path between the 
poles of a powerful magnet. However, where the cyclotron uses 
positive particles, the accelerator works on negatively-charged 
electrons. They start from a hot filament, inside a doughnut- 
shaped vacuum tube, and magnetic forces from the alternating- 
current electromagnet whirl them around. It accelerates them 
steadily instead of in jumps across a gap, as in the cyclotron. 
The forces involved are really similar to those in a transformer, 
where there are two coils of wire around an iron core. When 
alternating current passes through one, the primary, an "in- 
duced" current is made to pass through the other, called the 

An electric current in a wire is a flow of electrons, so in the 
secondary of a transformer there is such a stream. In the ac- 
celerator these electrons flow not along wires but in the open 
space inside the vacuum tube, until they have nearly the speed 
of light. Then they can be made to fall on a metal target and 
there are X-rays of the same high voltage, greater than any 
hitherto created. But the electrons themselves can also be 
brought outside the tube and used, for example, to bombard 
atomic nuclei. They offer great possibilities for biological work 
as well, since they may be sent right into the body. No one yet 
knows what their results will be; but the electron accelerator 
offers every possibility of being one of the powerful new tools 
of science in the future, for it permits experiments with the 
high-velocity electrons to keep pace with those of the positive 
particles from the cyclotron. We will be hearing more about 
the electron accelerator in years to come. 

XX. New Sources of Power 

Our civilization is based on power; not the power of a des- 
potic group to bend other men to their will, but the power that 
drives the machines in our factories, that drives our trains 
across the country, our ships over the waves and our airplanes 
through the sky. From 1920 to 1940 the total production of 
electrical energy in the United States rose from 43 billion to 
145 billion kilowatt hours. Yet even this is not enough, and the 
output is being increased at a greatly accelerated rate. This aug- 
mented power will come, as does all our power, from the sun 
some, perhaps, in a direct conversion of solar radiation into elec- 
tricity, the rest by the indirect means we now use. Perhaps it is 
not at once obvious that this statement is true. However, a little 
consideration reveals that it is. 

Water power? Surely this comes from the sun, whose rays 
warm the waters of the ocean and lakes, evaporating them so 
they are carried through the air and fall on high ground as rain. 
In returning to the ocean they may operate turbines and drive 
generators on the way. 

"How about windmills?" one might inquire. Yes, here too the 
sun is the source, for its warming rays produce the areas of 
different temperature and pressure in the atmosphere that 
make the winds blow from one place to another. 

Similar is the case of boilers fired by coal or oil. These fuels 
are the remains of vegetation of past geologic ages, which grew 
and acquired energy through their leaves from the sun in the 
process of photosynthesis. The same thing, of course, is true of 
the gasoline burned in internal combustion engines. 

Also there is tidal power. The moon, as well as the sun, is 
responsible for the tides; but many astronomers think that the 
moon was originally a part of the earth which was pulled out 



of our globe by earlier tidal forces, originating with the sun. 
While, at the present time, there is no entirely satisfactory 
theory to explain the origin of the earth and the other planets, 
it may well be that our globe was originally part of the sun; and 
in that event, even if power from atomic sources is someday 
achieved, that also would have a solar origin. 

At the present time, we are still mainly dependent upon in- 
direct connection with the sun, and are following the path 
pioneered about two centuries ago by Newcomen and bv Watt. 
Steam is an important step in the process; from the earlier re- 
ciprocating engines in which steam was admitted to a cylinder 
to push on a piston, and was then exhausted as the piston re- 
turned to prepare for another push, we have the highly efficient 
steam turbine. In the turbine the push is continuous, like a 
steady wind spinning the blades of a windmill, but many re- 
finements have been made to get the greatest possible amount 
of energy out of the steam. Water boils at 100 Centigrade (or 
212 Fahrenheit) and that is the temperature of the steam in 
an ordinary teakettle. If the temperature is lowered beneath 
that figure, at ordinary pressure it condenses back to water; but 
the steam can be further heated and more and more energy put 
into it. 

To get this energy out in the form of motion of a shaft, it is 
not sufficient merely to squirt the jet of steam against windmill 
blades. The modern turbine, which traces its invention back 
half a century to Sir Charles Parsons, uses the same steam over 
and over again, driving a whole series of windmills. Heated to 
nearly 1000 Fahrenheit, it is driven through carefully designed 
nozzles and against curved blades in the rotor which are de- 
signed with equal care. These blades are curved, and them- 
selves act as jets to shoot the steam back again. This gives 
a reaction, like the kick of a gun or the expanding gases of a 
skyrocket, and adds more drive to the spinning wheel. But still 
the steam has not done all its work. It passes through a series 
of stationary blades, curved in the opposite direction from those 
of the rotor, and emerges to strike against still another spinning 


set and the same process takes place again. This may be re- 
peated a dozen times. At each stage the steam, originally highly 
compressed, expands as it gives up energy, so each rotor is 
larger than the one before. The steam, at the end, emerges 
at atmospheric pressure and about as hot as boiling water. 

Ten years ago temperatures of about 750 Fahrenheit were 
the highest that could be used commercially, for, even though 
engineers realized that higher temperatures would mean higher 
efficiencies, the turbine blades would not survive. The heating 
produced molecular changes, and they would easily break with 
the high centrifugal forces to which they were subjected. Now 
new alloys have been developed that retain their strength up to 
1000 Fahrenheit, where they begin to become red hot, and 
these have been used in one of the newest installations. This is 
the General Electric turbine generator which was recently in- 
stalled in the Twin Branch station of the Indiana and Michigan 
Electric Co., which is located near South Bend, Indiana. 

Steam is fed into the high -pressure unit at 940 Fahrenheit 
and a pressure of 2300 pounds per square inch, which is the 
highest ever used in an electric-utility generating station in the 
United States. The rotors spin at 3600 revolutions per minute. 
The previous record for steam pressure 1400 pounds was 
held by two G-E machines, installed by the Pacific Gas and 
Electric Company less than a year before. The chief engineer 
of the Indiana company, Philip Sporn, has reported that the 
new high-pressure unit consumes just a pound of Indiana coal 
to give one kilowatt-hour of electrical energy. The average tur- 
bine, as used today, requires two-thirds more heat for the same 
output. After the steam emerges from the unit, it is reheated to 
900 Fahrenheit, then fed into a low-pressure turbine which 
revolves at 1800 rpm, thus making use of the energy that re- 

The possibility of further increase is indicated by tests that 
have been conducted on new alloys that retain their strength 
up to 1100 Fahrenheit. These contain iron; but they are not 
classed as steel, because they contain no carbon. 


In general, a thermodynamic cycle such as that involved in 
heating water, making steam, running an engine and condens- 
ing the exhaust steam to water again, is more efficient the 
greater the range of temperature through which it operates. 
But there are practical limits to the efficiency that can be ob- 
tained by heating the steam above the boiling point. This diffi- 
culty can be overcome by using a binary cycle; that is, by em- 
ploying two different vapors, one of which has a much higher 
boiling point than the other. Of all other vapors besides water, 
mercury, which boils at 675 Fahrenheit, has proven best. 1 

Today's mercury boiler unit has an oil-fired boiler which 
vaporizes the mercury. The vapor drives a turbine, then is con- 
densed back to a liquid again as it passes next to pipes through 
which water is flowing. The heat, which is thus transferred to 
the water, changes it to steam, and this in turn is superheated 
by the exhaust gases from the mercury boiler. This then drives 
a series of steam turbines of the usual type. 

One of the problems which seriously hampered the use of 
binary cycles by large plants was the attack of the mercury on 
the steel tubes of the boiler, and the formation of lumps of 
an iron crystalline deposit which plugged the tubes. After ex- 
tensive research it was found that by dissolving small amounts 
of magnesium and titanium in the mercury, and by keeping all 
oxygen out of the system, this difficulty could be eliminated. 
Two of the largest commercial units have been redesigned to 
take full advantage of this improvement. One of them (that 
at Schenectady) now produces a kilowatt hour for each half- 
pound of fuel oil that is burned which is a new record, and is 
about ten per cent better than the most efficient all-steam 
plants. In the other (at Kearny, N.J.) 21,000 kilowatts are pro- 
duced by the mercury and 30,000 from the steam. Engineers 

1 In 1913 the first experimental model of a mercury boiler for power was made 
by a General Electric engineer, Dr. William LeRoy Emmet. Studies with this led 
to the first commercial unit ten years later, built for the Hartford Electric Light 
Company, to deliver 1800 kilowatts. Later a larger one, of 10,000 kw, was made 
for the same company; then, in 1932 and 1933, 20,000 kw plants for the G. E. 
Schenectady works, and for the Kearny station of the Public Service Electric 
and Gas Company of New Jersey. 


predict that with the data now secured it would be possible in 
a new plant to produce a kilowatt-hour of electrical power with 
0.41 pounds of fuel oil. 

As a foretaste of what the future may bring there is also the 
gas turbine, in which the vapor stage (whether of mercury or 
steam ) is eliminated and a stream of hot gases drives the turbine 
blades directly. A pioneer experimenter with this is Dr. Sanford 
A. Moss, whose turbosuper charger for airplanes has already 
been described. The motive power of the supercharger comes 
from a gas turbine, driven by exhaust gases from the engine. 

The gas turbine is used on the ground as well. It has been 
employed in oil refineries, for instance, where there is a copious 
supply of hot gases, formerly wasted. Thus its main application 
has been to produce useful power as a by-product. Perhaps some 
day, however, oil or coal will be burned not to make steam but 
to produce hot gases to give the turbine blades their push, and 
the energy wasted in the intermediate vapor stage will be saved. 
But there are still many problems to be solved before this can 
be accomplished. 


Such developments as the mercury boiler have come because 
engineers do not like to see power, or anything else, wasted, 
and they have looked longingly at the many places in nature 
where power is consumed without doing useful work. The fall- 
ing of water over Niagara Falls is an example. Probablv few, 
even among engineers, would deny the aesthetic value of those 
falls or urge their complete abolition and dedication to power 
production the fate which other falls, like those at Trollhat- 
tan, in Sweden, have suffered. But without disturbing the 
beauty of Niagara, large amounts of power to drive important 
war production both in the United States and Canada have 
been generated from water that is diverted from the falls to 
drive hydraulic turbines as it drops to the level of Lake On- 


Less steady than the falling of water is the movement of the 
atmosphere in wind. The windmills used on American farms 
for raising water can operate only occasionally and still keep 
storage tanks filled; but if the windmill is to be a useful source 
of power for industry, it must be more regular. To help attain 
this end, it can be installed in a place where winds blow a large 
proportion of the time. Such an experiment is being carried out 
on top of a 2000-foot summit, called Grandpa's Knob, in Ver- 
mont. Designed to give 1000 kw (more than 1300 horsepower) 
it has two enormous blades. Sixteen feet in maximum width, 
they are as big as the wings of a bombing plane and about 
the same shape, too, for they have been designed in strict ac- 
cord with aerodynamic principles. They weigh seventy-five 
tons, and, mounted at the top of a 100-foot tower, they sweep 
about a circle 175 feet in diameter. 

It is estimated that the installation on Grandpa's Knob will 
produce current about half the time through the year. This will 
feed into the lines of the Central Vermont Public Service Com- 
pany. To keep the output uniform while the windmill is run- 
ning, it is designed so that it maintains a speed of thirty revo- 
lutions per minute whether there is a gale of seventy miles per 
hour or a breeze of fifteen miles per hour. This is accomplished 
by automatic feathering; that is, the pitch, or the angle which 
the blades present to the oncoming wind, is changed with the 
alterations in wind velocity. Although it takes a short time for 
the blades to shift after the wind changes, they are so massive 
that they act as a flywheel; inertia keeps them turning at a con- 
stant rate. 

The generator will not be a primary supply for the Central 
Vermont Company, but rather an auxiliary source, supplement- 
ing others already in use. Much of the company's energy is now 
obtained from water power, and the water, impounded behind 
dams, can be used when the wind is not blowing. Conversely, 
when the wind generator is running some of the water can be 
saved. Since wind studies on other Vermont peaks have already 
been started, it has been suggested that, if the Grandpa's Knob 


installation is the success that its designers hope it to be, New 
England's mountains may eventually have as many windmills 
as Holland. 

Power from the ocean is another possibility that has engaged 
the attention of many scientists. A few years ago the world was 
interested in the experiments in the West Indies of the French 
physicist, Georges Claude. It is possible to run a heat engine, 
analogous to a steam engine, with relatively small temperature 
differences. Even though the efficiency is not high, if you can 
get large quantities of warm and cool water without cost you 
may be able to produce power economically. So Claude made 
use of the difference in temperature between the warm water 
at the surface of the Caribbean Sea and the cooler water from 
the depths. He was actually able to get power, but the trouble 
was that it took more power than he obtained to pump up the 
cooler liquid, so the process was hardly a feasible one. 

Waves too are thought of as a power source, but no satis- 
factory means of utilizing them has ever been devised. The 
movement of the tide seems somewhat more likely to give suc- 
cess, though the one-time plans for a great tidal power project 
at Passamaquoddy, Maine, have been laid to rest with little re- 
gret by engineers. Here the idea was to dam up two bays, mak- 
ing natural reservoirs. By keeping them at different levels and 
alternating between the two the direction of the water flow, 
it would be possible to keep the power output constant, regard- 
less of the variation in the heights and times of the tides. But 
other factors made the plan seem uneconomical. For one thing, 
the corrosion of the pipes and turbines by the sea water would 
be an expensive item. And there was still the need of dis- 
tributing the current generated, which often is considerably 
more expensive than the cost of producing it, even from coal 
or oil. 

Since all our energy comes from the sun, why not utilize the 
sun's rays directly? This is a question many have asked and have 


tried to answer; and several important researches aiming to an- 
swer it are now in progress. There is certainly plenty of energy 
there, for, in our latitudes, every square foot of ground on which 
the sun shines receives about a tenth of a horsepower. The 
average family could operate all its lights and electrical ap- 
pliances from the energy falling on a square yard of the roof. 
A factory could run its machinery with the energy its roof re- 
ceives provided it could all be utilized. 

The photovoltaic cell (it was described on page 178) converts 
light directly into electricity, but the efficiency is very low and 
the cells are fairly expensive to construct. Research, however, 
may improve both these factors. Then our deserts may be cov- 
ered with photovoltaic cells but once more, of course, comes 
the expense of transmission. Using the factory roof as a power 
source might eliminate this, for the output would then be con- 
sumed close to the point of generation. 

For many years Dr. Charles G. Abbot, secretary of the Smith- 
sonian Institution, has been carrying on experiments using solar 
energy in a different way. It is the heat rather than the light 
that he employs. The most satisfactory results have been ob- 
tained by employing a long sheet of polished metal bent to the 
shape of a parabola, so that the solar rays are focused along a 
line down the middle of the reflector. At this position is a pipe, 
blackened on the outside to make it absorb all possible heat, 
which acts as a boiler. It is a boiler of the "flash" type that is, 
it is kept hot, and water is admitted a little bit at a time, so that 
it immediately vaporizes. The steam can then be used to run 
a small engine. Of course the sun moves across the sky, so it 
is neccessary to move the reflector. Dr. Abbot arranged the 
device on a slant, with the boiler parallel to the axis of the 
earth; the reflector, driven by clockwork to keep it aimed sun- 
wards, turns once a day around the boiler as a center. Some 
experts have expressed doubt whether the efficiency of fifteen 
per cent of such a plant in producing electrical energy, which 
Dr. Abbot has attained, can ever be much exceeded. 


However, when it comes to heating rather than power pro- 
duction, this method seems more likely to succeed. For many 
years, at an observing station maintained by the Smithsonian 
Institution at Mt. Wilson in California, Dr. Abbot had in opera- 
tion a solar cooker. As in the power plant, av long parabolic re- 
flector gathered the sun's heat rays and focused them on a pipe. 
This was not a boiler; through it circulated oil which, when 
heated, traveled up to an oven, which it maintained at a high- 
enough temperature to cook with. After the oil had given up 
its heat, it moved down to the bottom of the heater again. By 
having a large insulated storage tank for the hot oil, Dr. Ab- 
bot was able to keep the oven hot during the night, and cooking 
could be done at any time. 

An extensive program of research on utilizing solar energy 
has been inaugurated at the Massachusetts Institute of Tech- 
nology at Cambridge, and an experimental house has been built 
there to test the practicability of heating, and even cooling, 
houses with the sun's rays. It may seem contradictory that a 
house could be cooled with heat, but both cooling and heating 
are essentially the same. Both are the transfer of heat from one 
place to another. In the mechanical refrigerator, you take heat 
from inside the box and dissipate it outside. In the type with 
water connections, the heat warms the water, which then 
drains away; while in the independent type, which just requires 
plugging into an electrical outlet, the heat raises the room tem- 
perature as the refrigerator temperature goes down. When a 
theater or restaurant is air conditioned in summer, the inside of 
the theater is cooled but the out-of-doors is warmed. An air- 
conditioning system can be used, with very little change, to 
warm a building in cold weather. Then the heat from the out- 
side (which is thus made still cooler) is carried inside simply 
the summer process in reverse. 

To make such a transfer of heat requires energy, and in the 
electric refrigerator this is supplied by the electrical current. 
But in one non-electrical type, the Electrolux, a gas flame sup- 


plies the energy. Where there is no gas supply a kerosene flame 
works as well; only a slight modification would be needed to 
use solar heat instead of a flame. 

Following is an extract from a statement issued by M.I.T. in 
announcing one of several projects planned under the solar- 
energy program made possible by a gift, in 1938 from the Cabot 
Fund, of $650,000 for research on the utilization of solar radia- 
tion for the tasks of man. (These projects are carried on under 
the direction of Prof. Hoyt C. Hottel, of the department of 
chemical engineering.) Says the Institute: 

The purpose of the investigation is to study various uses for solar 
heat, including winter house heating, summer air conditioning and 
power generation. In the basement of the specially designed labora- 
tory house is a large well-insulated water storage tank which will be 
used for ironing out the fluctuations in a source so variable as the sun. 
The building's heating system consists of a method of forced air 
circulation so arranged that the flow of air can be either over the 
hot tank surface, or through the coils of the refrigeration system to 
be installed later. The refrigeration system, operating on an absorp- 
tion principle, will utilize sunlight as its heat source. 

While the Technology engineers are well aware that the amount 
of solar heat in New England would make domestic heating by solar 
radiation uneconomical in comparison with other sources of heat, 
there is sufficient sunshine in this region to test the efficiency of heat- 
ing systems for localities where the climate is less rigorous. 

Professor Hottel explained that, although several types of energy 
collectors, or "heat traps," are to be tried in the Technology research 
program, first attention is to be given to a shallow, box-like heat col- 
lecting device placed in a recess on the roof of the building. The 
bottom of the box is a thin sheet of metal painted black to absorb the 
utmost amount of solar energy. Firmly fixed to the under side of the 
sheet is a series of small thin-walled metal tubes which are heated by 
contact with the sheet and which in turn heat water circulated through 

The box has several covers of glass, interspaced with dead air 
regions, through which nearly all the sunlight can pass, but back 
through which little heat can escape. The sunlight is converted into 
heat when it strikes the metal sheet. Beneath the box is a layer of 
mineral wool to prevent the escape of heat in that direction. 

After the water has been warmed in the heat collector, it passes 


through carefully insulated pipes to the storage tank in the basement. 
The tank is so thoroughly insulated that it will lose little heat over 
long periods of time. Depending on the size of the tank, water can 
be kept hot from a few weeks to a half year by this method. To use 
the heat in the storage tank for heating purposes, a system of forced 
air circulation is employed in which the air passes through ducts, one 
wall of which is the hot side of the tank. 

Several methods of operating such a solar heating system are to be 
studied at the Institute. A sunlight collector large enough to heat the 
house directly might be used, thus making necessary only a small 
storage tank to heat the house during periods of a few weeks when 
the weather was cloudy. Or a small collector might be used, and heat 
stored all summer in a tank large enough to hoard an entire winter's 
supply of heat. 

Part of the research at the Institute will be to study these methods 
of operation and also to study the most efficient types of paint to use 
on the collecting devices, the most effective number of glass plates to 
use over the collector, and the best angle of roof slope to meet the 
requirements of various types of heaters. The roof on the Institute's 
sun laboratory slants at an angle of 30 degrees with the ground. The 
greater the number of glass plates used, the greater the insulation 
against heat loss, but each additional plate cuts down by about eight 
per cent the amount of sunlight which may pass through to the ab- 
sorbing sheet. 

On the Institute's agenda are several other solar energy re- 
searches. One is on the use of photoelectric cells; another will 
employ the thermoelectric effect. Suppose you take two copper 
wires running from a galvanometer (which is merely a very 
sensitive electric-current meter) and join an iron wire between 
their ends so that there are two iron-copper junctions. This is 
called a thermocouple. If one of these junctions is put in hot 
water, the other in ice water, a current will flow and will be 
indicated by the galvanometer. The same thing will happen 
when one of the junctions is left in the air, at room tempera- 
ture, and the other is heated in a gas flame. Or the thermocouple 
could also be heated with the sun's rays, focused by a lens; and 
then you would have the solar radiation converted into elec- 


tricity. Professor Hottel has discussed this in an article in which 
he said: 2 

The phenomenon involved here has itself long been known; many 
investigators have been led to speculate upon it as a possibility for 
large-scale thermoelectric power production, but then to dismiss it 
as unimportant because the effect is so small. The recent discovery, 
however, of several alloys or compounds having the desired combina- 
tion of low electrical resistance, low heat conductivity and high 
thermoelectric effect has made it distinctly interesting from an engi- 
neering as well as a scientific point of view. 

Such compounds as lead sulfide with bismuth sulfide, or bis- 
muth and antimony sulfides, prepared by the methods of pow- 
der metallurgy, have proved quite promising. With them an 
efficiency of five per cent has been achieved in converting 
thermal to electrical energy, with heat available at 450 Centi- 
grade and thrown away at 25 Centigrade. Of course, the de- 
velopment of highly efficient thermocouples affords many op- 
portunities other than those involving solar power. They offer 
the hope ( a most distant one, to be sure ) that some day boil- 
ers, steam engines and electrical generators will no longer be a 
stage in converting the heat of coal or oil into electricity. In- 
stead, the flames may heat thermocouples, and current will flow 
without the wastefulness of the intermediate steps. 

Or, as Professor Hottel has pointed out, the process may be 
used the other way for cooling. When current is made to flow 
through a thermocouple, a difference of temperature is pro- 
duced between the two junctions. If the warm junction is at 
room temperature, there is thus a refrigerating effect. He has 
found it possible to produce temperature differences as great as 
40 Centigrade by this means, and he foresees the possibility 
of cooling with heat in a very simple way: that is, "generate 
electricity thermoelectrically by use of a high and intermediate 
temperature, then use that energy in a second thermoelectric 
unit to obtain a low and an intermediate temperature and thus 
obtain a heat-operated refrigerator/' 
2 The Technology Review, Vol. 42 (March 1940), p. 195. 


The principal uncertainty in such speculations is that science 
still has very slight knowledge of what happens when elec- 
tricity is generated at a thermocouple. Theoretical researches 
into this are going on, and as a result it may be possible to 
predict whether it is likely that alloys may be discovered to 
make feasible such a process of power production, or whether 
there is some insurmountable barrier to its attainment. 

What seems to be the best approach to using solar energy 
and this forms one of the main parts of the M.I.T. program 
is by imitating, or perhaps surpassing, the process by which 
nature uses it in living plants. Chlorophyll, the green coloring 
matter, absorbs light energy and uses it to convert carbon diox- 
ide and water into carbohydrates, which in turn are used for 
food to keep animals alive. This is the most important of all 
chemical processes, but its details are not understood. 

In speaking to the American Chemical Society on the sub- 
ject, Professor C. C. Furnas, of Yale University's Sterling Chem- 
istry Laboratory, said that the basis of this process seems to be 
some simple photochemical reaction such as one in which water 
and carbon dioxide and radiant energy react to form formalde- 
hyde and oxygen. He continued: 

The formaldehyde immediately forms simple sugars which then 
serve as the basic material for the multitude of complex compounds 
in plants. What we should like to do would be to take some such 
simple compound as formaldehyde formed with the help of radiant 
energy, put it into an electro-chemical cell, expose it to oxygen, and 
then reverse the above reaction and get back the stored energy as 
electrical energy at high efficiency. Formaldehyde can be oxidized 
in a cell in a basic solution to give formic acid and a small amount of 
electrical energy. Perhaps all that is needed is a proper catalyst to 
complete the oxidation to carbon dioxide and water and get back all 
the stored energy. 

The catalyst which nature uses for performing the photosynthesis 
is chlorophyll. That's the best catalyst known, but it is very poor. 
Plants are very inefficient stores of energy. Even the most luxuriant 
plants have an energy storage efficiency of less than two per cent. 
We ought to be able to do a lot better than that. 

It is a wide open field, this study of photosynthesis and the study 


of oxidation cells which will reverse the reaction. That is the reason 
it is hopeful. The systems which might be used would not have to 
be limited to organic compounds. It may well be that inorganic com- 
pounds offer the most hope. The satisfactory system would be one 
that is as light sensitive as the chemicals on a photographic film, as 
easily reversible as a lead storage cell. The storage of the energy 
would be simply that of storing chemical compounds. We are used 
to doing that with coal. 

A possible clue has been found by one of the Cabot Fund re- 
searchers, Dr. Eugene Rabinowitch, who is seeking organic 
dyes that might perform a function similar to that of chlorophyll 
in plants. A purple dye called thionine, and methylene blue, are 
two that work. There are two iron sulfates, the ferrous and the 
ferric forms. The former consists of an iron atom linked with a 
sulfate "radical" which is made of a sulfur atom with four oxy- 
gens. Ferric sulfate has two iron atoms with three sulfates. Un- 
der the influence of light and one of the dyes, ferrous sulfate is 
changed into ferric sulfate. 

Since the iron atom has a positive charge and the sulfate ion 
(as the sulfate radical is called when it breaks off in solution) is 
negative, there is an excess of negative charge in ferric sulfate, 
while it equals the positive charge on the iron ion in the ferrous 
sulfate. Immersing two metal electrodes into a ferric sulfate 
solution, and exposing one to light while the other is kept in 
the dark, makes an electric cell which yields a small current as 
long as the illumination continues, found Dr. Rabinowitch. The 
ferric salt forms around the electrode on which the light shines, 
and reverts to the ferrous sulfate around the dark electrode. 
If the two electrodes are connected by a wire, electrons flow 
in other words, there is an electrical current. 

According to reports of Dr. Rabinowitch's work, the ef- 
ficiency of such a light cell is very low, about a tenth as much 
as that of chlorophyll which itself is quite inefficient, since it 
uses only about one per cent of the light energy that falls upon 
the leaf. But at least this research may point the way; now that 
science has some idea of what to look for, more efficient con- 


verters than the thionine and methylene blue may be dis- 

Whether we succeed, by methods such as these, in getting 
energy more directly from the sun, or whether we use it in the 
form of coal, oil or water power, there is still a lot of power lost 
between the sun and us. At the solar surface every square inch 
is sending out some sixty horsepower. It is broadcast freely in 
all directions, and only %,o 00,0 00,000 is intercepted by our 
planet. By far the greater part of the sun's output is distributed 
promiscuously out into space. 

Carrying the problem back a stage, we might well ask how 
the sun itself keeps going. Only in the last few years have 
astronomers found what seems to be a satisfactory answer 
one given by the studies of Dr. Hans Be the, of Cornell Uni- 
versity. The sun is really an enormous atom-smasher. With 
temperatures at its heart of around 20,000,000 Centigrade and 
pressures about 15,000,000,000 pounds per square inch, strange 
things happen things which we can hardly hope to imitate. 

According to the modern conception, there are six stages in 
the atom-smashing process of the sun. Hydrogen is the fuel, 
helium is the ash. Carbon is the catalyst which makes the 
process possible; during the series it changes to nitrogen, then 
returns to carbon at the end. Some of the steps occur in a few 
minutes, others in thousands or millions of years. It would take 
several million years, on the average, for any one carbon atom 
to yield a helium atom. 

Fortunately, there happen to be such a vast number of atoms 
in the center of the sun that the production of other atoms, 
along with energy, proceeds at enormous intensity. It all takes 
place in the nuclei of the atoms, from which the outer elec- 
trons have been completely stripped off. Starting with a nucleus 
of the most common kind of carbon, of mass 12, a hydrogen 
nucleus (a proton) comes along, unites with it to form nitrogen 


of mass thirteen. Energy, in the form of a gamma ray, is given 
off. But nitrogen 13 is unstable; in ten minutes it gives off a 
positive electron and turns into carbon of mass 13, an isotope 
which makes up a little less than one per cent of ordinary 
carbon. A positive electron comes off. Then, 50,000 years later, 
another proton happens by, unites with the carbon 13, trans- 
mutes it into nitrogen 14, the kind that makes up nearly one 
hundred per cent of nitrogen in the air. Again energy is radi- 
ated, as another gamma ray. 

The nitrogen 14 has quite a respectable life of 4,000,000 
years before it changes. When it does, a proton is again the 
agent. It turns into oxygen 15, and another gamma ray is 
emitted. But oxygen 15 is unstable; only two minutes are re- 
quired for it spontaneously to decompose into nitrogen 15 ( the 
isotope which makes up about 0.14 per cent of the ordinary 
gas), and to give up another positive electron. After twenty 
years the nitrogen 15 changes, with the aid of a fourth hydro- 
gen nucleus, into carbon 12 and helium. The latter is not 
changed, but the carbon is ready, after 2,500,000 years, to 
join with a proton in starting the cycle all over again. 

The sun's fuel is hydrogen, which is used up, and it contains 
enough to keep it going for many billions of years to come. Per- 
haps, also, it picks up hydrogen in its journey through space; 
and if so, the sun's life may be even longer. 

Although there is no hope of duplicating such a process as 
this on earth, within the last few years it has begun to appear 
that a form of atomic energy may eventually be made avail- 
able by man. Before 1939 all known nuclear reactions produced 
relatively small amounts of energy, considerably less than that 
required to produce the atomic bullets to instigate the reaction. 
Then experiments in Europe, soon confirmed in the United 
States, revealed that neutrons, moving slowly and with little 
energy, are able to make nuclei of uranium, the heaviest ele- 
ment, divide into two parts; two other nuclei of, for example, 
krypton and barium, elements of medium weight. But most sig- 


nificant is that in the process more neutrons are emitted, along 
with a large amount of energy. 

Physicists realized immediately the exciting possibility which 
this heralded. For if the neutrons given off could be used to 
break more uranium nuclei, a chain process could be started 
which would keep on going by itself. Since fast neutrons have 
no effect, because they go right on through the atomic nuclei, 
those coming from the dividing process would have to be 
slowed. But this could be done by immersing the uranium in 
water. Then the water would absorb the energy given off, and 
the steam generated could be used to provide power. To stop 
the process all that would be needed, apparently, would be to 
lift the uranium out of the water. 

Ordinary uranium will not act in this way, so scientists sus- 
pected that only one of the three isotopes of which it is made 
will show the effect the others inhibiting it in some w?y. In 
the spring of 1940 Dr. Alfred O. Nier, at the University of 
Minnesota, and Drs. K. H. Kingdon and H. C. Pollock, at the 
General Electric Research Laboratory, succeeded in separat- 
ing minute quantities of the uranium isotopes. They used mass 
spectrometers. Starting with uranium tetrachloride, they vapor- 
ized it in a tiny oven, let it emerge through a tiny slit. There 
the vapor was bombarded by electrons to make uranium ions 
out of it. With the whole apparatus placed in a powerful mag- 
netic field, the ions curved around as they were accelerated by 
an electric field. Since the lighter ion paths curved most, the 
different isotopes were thus sorted out and collected on plati- 
num plates at the end of a copper tube. 

Ordinary uranium consists mostly of an isotope of mass 238; 
that is, 238 times as much as hydrogen. About one part in 140 
is an isotope of mass 235 and one part in 17,000 of mass 234. 
Though almost infinitesimal amounts of the pure isotopes 235 
and 238 were isolated by the experimenters in Minneapolis and 
Schenectady, these were enough to test. The samples were 
sent to Dr. J. R. Dunning, of Columbia University, who fired 


slow neutrons from the cyclotron at them. The amounts ob- 
tained were not enough to make a test of the chain-reaction 
process; but it was determined that uranium 235 was the one 
which divided under the bombardment. 

Since then, the problem has been to isolate enough U235 to 
make a real test. It is known that intensive research has been 
carried on since the first announcements in 1940, but with re- 
sults not revealed; the initial steps of the experiment were 
necessarily undertaken in wartime secrecy. One can only infer 
that the mass spectrometer is not being heavily relied on, for, 
at its former rate of production, to extract a pound of the stuff 
by that means would take 12,000,000 years! If U235 will behave 
in the way expected, manifesting the chain reaction . . . but 
that remains one of the big "ifs" of science, which has en- 
countered so many "ifs" and turned them to advantage. Mean- 
time, however, the following words of Dr. Kingdon, written 
in 1940, are still to be heeded: 

"While it seems unlikely that this energy source will displace 
our present means of getting power, it cannot be denied that 
such a source should have important implications, as it is esti- 
mated that several million times as much power could be ob- 
tained from U235 as from an equal weight of coal. These ap- 
plications will involve problems of proper control of the power, 
and protection against the tremendous neutron and X-ray radia- 
tions which will accompany it. It may be that the use of these 
radiations in therapy will be one of the most important applica- 
tions. But detailed discussion of these questions is premature 
until further progress has been made. . . /' 


See Text, Page 67 

Natural rubber is made of long molecules like this ( each C repre- 
sents a carbon atom and each H a hydrogen atom ) : 

H H H 


H X C X H H H X C X H H H N C X H H 

... C-C = C-C~C-.C==C--C--C-C==C-C ... 

H H H H H H 

This is really a repetition of a single link, or "monomer," 


H N C X H H 

C = C - C = C called ISOPRENE. 


The arrangement H I H is called a "methyl" group, and another 
can be attached ^c' in place of the other H in the middle, 
thus: I 

H H 
H N C X X C X H and this is called 


d = L C = C 
I I 

H H 

When this monomer is linked together, we have a chain molecule, 
or "polymer," which is methyl rubber, used by the Germans during 
World War I. But both isoprene and dimethylbutadiene are really 
modifications of a simpler monomer, with an H in place of each 
methyl group: 


H H H H 

C = C - C = C which is called BUTADIENE. 

I I 

H H 

Linking together, or "polymerizing," this unit gives us a synthetic 
rubber which has been used in Russia and also, formerly, in Germany, 
under the name of Buna 85 and Buna 115. However, one of the 
middle Hs in butadiene can be replaced by an atom of chlorine ( Cl ) : 

H Cl H H 

C = C - C = C called CHLOROPRENE. 

I I 

H H 

The polymer of this was the first successful American synthetic rub- 
ber, Neoprene, and it has also been made in Russia under the name 
of Sovprene. 

Six carbons and six hydrogens may be linked together in a ring: 


H C H 

^C* X C X which is BENZENE, 

! II 

C C 

tf ^z' ^K 


H H 

and when this is attached to a vinyl group: C=C which 

is really half of a butadiene monomer, like i 


H H 
I I 
C = C 

: '-.:.: ^ n -, ' 1 

H // \ H we have vinylbenzene, or 


C C 

H' V N H 



Now we can make a chain with alternate links ( called a "co-polymer") 
of styrene and butadiene, in which the units are like this: 

H H H H H H 

I I I I I I 

C-C-C C = C- C 

Ill I 

H H H 

(The hexagon is a short way of indicating the 
benzene group of 6 carbons and the connected 
hydrogens. ) 

This is a synthetic rubber widely used in Germany as Buna S; and 
its manufacture in the U.S. has begun. Or instead of styrene, we can 
take another group, in which carbon and nitrogen CN take the place 
of the benzene ring: 

H H 

Q ___ Q which is vinyl cyanide, or 


H C^N 

and alternating this with butadiene we have the unit: 

H H H H H H 

I I I I I I 

C-C=C_C C-C 

H H H C = N 

made in Germany as Buna N and in the United States as Perbunan, 
Chemigum, Ameripol and Hycar. 

A third co-polymer may be made with a group of 4 carbons and 8 
hydrogens; including two methyl groups: 



1 ^ H 

C = C called ISOBUTYLENE, 

I X H 



which, when alternated with butadiene, is: 


H I H 
H H H H N C X H 

I I I I I I 

. c c=c- c c-c 


H H X C N H 

H | H 


and this is reported to be the structure of Butyl Rubber. Also, 
isobutylene itself may be polymerized; and this has been prepared 
under the name of Vistanex. Unlike most synthetic rubbers on the 
market, butadiene is absent in Vistanex. Using the vinyl group at- 
tached to chlorine, 

H H 


Cl H 

we can make up a polymer which is sold as Flamenol and also as 

Another synthetic rubber is called Thiokol, and is distinguished by 
the presence of sulfur. In one form the units of the polymer are: 

H H S 


,..c = c-s s 




Abbe, Ernst, 149 
Abbot, Charles G., 274 
Accelerator, induction electron, 265 
Acetone, 76 
Achromatic lens, 148 
Acid, ascorbic, 105 

nicotinic, 104 

oxalic, 80 

pantothenic, 95 

para-aminobenzoic, 109 

picric, 16 

sulfuric, 8 

thioglycollic, 57 
Acrylic resins, 43 
Acrylonitrile, 287 
Adaptability of eye, 210 
Additive color mixture, 229 
Aerial color photography, 234 
Agfacolor, 233 
Air Corps, U.S.A., 234 
Airgraph, 238 
Airplane detection, 168 
Airplanes, plastic, 42 
Alchemists, 11 
Alchemy, 255 
Alcohol, 36 

methyl, 77 

Alexanderson, E. F. W., 194, 201 
Alkyd resins, 45 
Alleviation, 57 
Allegheny Ludlum Steel Corp., 118, 

Alloys, 111 

high temperature, 269 
Alnico, 123 
Alpha particles, 257 
Alpha-tocopherol, 101 
Alumina, 114 
Aluminum, 112 

Aluminum Company of America, 115 
Alunite, 114 
AM, 189 
Amatol, 17 

Amber, 35 

American Chemical Society, 34, 64, 69, 
80, 96-97, 109, 185, 213, 279 

American Cyanamid and Chemical 
Corp., 18 

American Home Products Corp., 110 

American Optical Co., 150 

American Physical Society, 262 

American Viscose Corp., 51 

Ameripol, 66, 287 

Amerith, 37 

Ameroid, 72 

Ammonia process, synthetic, 13 

Ammonium picrate, 16 

Amplitude modulation, 189 

Anaconda Copper Co., 120 

Ansbacker, S., 109 

Aralac, 50, 73 

Armstrong, Edwin H., 188 

Ascorbic acid, 105 

Asphalt, 25 

Atlantic Research Associates, 73 

Atlas Powder Co., 18 

Atom, 4, 255 
structure of, 171 

Atomic energy, 282 

Atom-smasher, 259 

Australian Institute of Automotive En- 
gineers, 31 

Autogiro, 157 

Bacon, Roger, 15 

Bainbridge, Kenneth T., 262 

Baird, John L., 195, 201 

Bakeland, Leo H., 38 

Bakelite, 38 

Bakelite Corp., 46 

Baking, 10 

Bausch and Lomb Optical Co., 150 

Bauxite, 112, 114 

Beam-splitter, 240 

Becket, F. M., 118 

Beer, 10 




Beetle- ware, 41 

Beggs, E. W., 219 

Bell Telephone Laboratories, 98, 167, 

183, 195, 201, 244 
Benalite, 78 
Benzene, 46, 286 
Bergius, Friedrich, 27 
Bergius process, 8 
Beriberi, 92, 97 
Berl, Ernst, 34, 83 
Bernoulli, Daniel, 156 
Beta rays, 264 
Bethe, Hans, 281 
Biotin, 95 

Birkeland, Kristian, 13 
Bitumen, 35 
"Black light," 120 
Blodgett, Katharine, 152 
Blood-clotting vitamin, 102 
Bohr, Niels, 256 
Bolton, Elmer, 64 
Bomb sight, 151 
Bombs, incendiary, 116 
Booster, 17 

charge, 14 

Bouchardat, Gustave, 63 
Boyd, T. A., 29 
Bragg, Sir William, 180 
Bragg, W. L., 180 
Brass, 112 
Bread, baking, 10 

enriched, 97 
Brearley, Harry, 117 
Brewing, 10 
Brisance, 16 
Broadcasting, 187 
Bromine, 129 

from sea water, 29 
Bronze, 111 
Bronze Age, 112 
Buckley, Oliver E., 206 
Buna rubber, 66, 286 
Bunsen burner, 5 
Burris-Meyer, Harold, 246 
Bursting charge, 14 
Burton, W. M., 25 
Butacite, 44 
Butadiene, 66, 286 
Butanol, 76 

Butter, Karl and Otto, 20 
Butvar, 44 
Butyl rubber, 67, 288 

Cable, coaxial, 204 

gun for cutting, 19 

telephone, 207 
Cadillac, 1912 model, 28 
California Institute of Technology, 152, 


Cambridge University, 170 
Camera, depth of focus, 241 

Electroplane, 241 

Schmidt, 237 

single-shot color, 231 
Candlepower, 210 
Cannon, magnetic, 18 
Caoutchouc, 59 
Carbide and Carbon Chemicals Corp., 

45, 51, 143 
Carboloy, 119 
Carbon cycle, 282 
Carnegie Corp., 98 
Carnegie Institute of Technology, 34 
Carnegie Institution of Washington, 


Carotenes, 103 
Carothers, Wallace H., 3, 51 
Carpenter, W. S-, Jr., 53 
Cartwright, C. Hawley, 152 
Carver, George W., 82 
Casein, 47, 72 
Cast phenolic resins, 40 
Catalysis, 7 

arsenic poisoning in, 9 

in gasoline refining, 33 
Cavendish Laboratory, 170 
Celanese, 37, 49 
Cell, photoelectric, 176 

photovoltaic, 178 
Cellophane, 50 
Cellufoam, 78 
Celluloid, 36, 142 

Celluloid Corporation of America, 37 
Cellulose, 78 

acetate, 37, 49 

coal and oil from, 83 
Central Vermont Public Service Co., 


Chadwick, James, 258 
Chardonnet, Count Hilaire de, 48 
Charlton, Ernest E., 181 
Chemical Foundation, 118 
Chemical light, 224 
Chemical Warfare Service, 46 
Chemigum, 66, 287 



Chemurgy, 70-77 
Chlorophyll, 279 
Chloroprene, 286 
Cholesterol, 108 
Chromium, 117 
Cierva, Juan de la, 157 
Circuit breakers, explosive, 22 
Clarke, Frank Wigglesworth, 133 
Claude, Georges, 273 
Coal oil, 24 

tar, 17 

Cold flame, 6 
Color mixture, additive vs. subtractive, 

Color photography, 228 

aerial, 234 

Color-sensitive emulsions, 228 
Columbia University, 98, 102, 115, 

134, 188, 258, 265, 283 
Columbus, Christopher, 59 
Combustion, spontaneous, 6 
Commercial Solvents Corp., 76 
Continental Lithographic Corp., 219 
Coolidge, William D., 123, 180, 212, 


Copper, 111, 120 
Corning Glass Works, 140, 223 
Cotton, 81 

linters, 82 

Cotton Research Foundation, 81 
Coupling developer, 231 
Cowgill, G. R., 100 
Cracking process, 25 
Crookes, Sir William, 168 
Crown glass, 149 
Crucible Steel Corp., 118 
Cryolite, 114 
Cryptoxanthin, 103 
Crystal detector, 172 
Crystals in textile fibers, 52 
Gullet, 139 

Cuprammonium process, 49 
Curie, Irene, 265 
Curie, Pierre and Marie, 265 
Cyclotron, 260 

dees of, 260 

Daguerre, L. J. M., 226 
Dairy industry, 70 
Dairy Industry, Bureau of, 73 
Davisson, Clinton J., 184 
Day, Arthur L., 150 

De Forest, Lee, 173 

Dentures, magnetic, 126 

Detector, crystal, 172 

Detonator, 14 

Deuterium, 258 

Developer, coupling, 231 

Deville, Henri Sainte-Claire, 113 

Diastase, 10 

Dieterich, L. M., 241 

Diode, 173 

Disney, Walt, 245 

Dispersion, 148 

Diving suits, glass insulation for, 146 

Dollond, John, 148 

Domagk, Gerhard, 86 

Domains, magnetic, 124 

Donath, W. F., 98 

Dorland, Roger M., 78 

Douglas B-19 bomber, 20 

Dow Chemical Co., 46, 116, 130 

Dowmetal, 116, 132 

Dreyfus, Henri and Camille, 49 

Dulux, 45 

Duncan, Robert Kennedy, 2 

Dunning, J. R., 283 

Du Pont Co., 18, 50-51, 63, 106, 143 

Du Pont, Eleuthere Irenee, 18 

Duprene, 64 

Duralumin, 115 

Dynamite, 12 

Eastman, George, 37 

Eastman Kodak Co., 37, 50, 149 

Ebonite, 38 

Eddy currents, 127 

Edgerton, Harold E., 236 

Edison effect, 172 

Edison, Thomas A., 37, 171, 211, 243 

Egloff, Gustav, 31 

Ehrlich, Paul, 86 

"Eighteen-eight," 118 

Eijkman, Christian, 94 

Einstein, Albert, 177 

Ekstrom, A., 195 

Elastomers, 36 

Electrolux, 275 

Electrolytic Marine Salts Co., 129, 134 

Electron, 171 

accelerator, induction, 265 

gun, 196 

microscope, 184 

multiplier tube, 177 



Electron (Continued) 

tubes, variety of, 176 
Electronic tube, long-lived, 208 
Electrons, free, 171 
Electroplane camera, 241 
Elvehjem, Conrad A., 95-96, 104 
Emmet, William Leroy, 270 
Enriched flour and bread, 101 
Enzymes, 9 
Ergosterol, 108 
Esters, 36 
Ethane, 24, 31 

Ethyl-Dow Chemical Co., 130 
Ethyl fluid, 129 

Ethyl Gasoline Corporation, 129 
Ethylene dibromide, 29, 129 
Evans, G. M., 88 
Explosive D, 16 
Explosives, 12 

high, 16 

in oil prospecting, 23 

peacetime uses of, 18 
Eyde, Sam, 13 
Eye, adaptability of, 210 

F value, 237 
Fabrics, glass, 146 
Factor W, 96 
Fantasia, 245 
Fantasound, 245 
Faraday, Michael, 1, 59 
Farbenindustrie, I. G., 27, 63, 86 
Farm Chemurgic Council, 70 
Federal Communications Commission, 


Fermi, Enrico, 265 
Fiber, casein, 73 
Fiberglas, 145 
Fink, Colin G., 134 
Firefly, light of, 224 
Firestone, F. A., 250 
Fischer, Rudolph, 231 
Flame, cold, 6 
Flamenol, 45, 68, 288 
Flameware, Pyrex, 140 
Flash powder, 235 
Fleming, J. A., 173 
Flint glass, 149 
Flour, whole wheat, 101 
Fluorescence, 197, 216 
Fluorescent lighting, 218 
in aviation, 220 

Flying Fortress, 162 

FM, 189 

Foamglas, 144 

Focal ratio, 200 

Focus, depth of, 241 

Fog removal, 163 

Ford, Henry, 61, 83 

Ford Motor Co., 50, 74, 182 

Foulger, John H., 107 

"Fourth kingdom," 35 

Fractionation, 11 

Franklin Institute, 143, 156, 233 

Freedman, Hyman, 126 

Frequency modulation, 189 

Frolich, Per K., 67 

Funk, Casimir, 94 

Furnas, C. C., 279 

Gaisford, W. F., 88 
Galorn, 72 
Gas, marsh, 24 

natural, 25 
Gasoline, 17, 25 

carbohydrates as source of, 34 

catalysis in refining, 33 

ethyl, 129 

hundred-octane, 31 
Gears, magnetic, 125 
Geiger counter, 264 
Geissler, Heinrich, 216 
General Electric Co., 40, 195, 270 
General Electric Research Laboratory, 
123, 152, 165, 174, 180, 183, 212, 
265, 283 

Generator, Van de Graaf, 259 
George, Roscoe H., 164 
Georgia School of Technology, 83 
Germer, L. H., 184 
Gladstone, William, 2 
Glass, 136-139 

crown, 149 

fabric, 146 

flint, 149 

high-test safety, 143 

insulating, 146 

optical, 147 

Pyrex, 140 

refractive index, 149 

safety, 142 

shrunken, 141 

tempered, 142 

Triplex, 143 



Glue, casein, 73 

Godowsky, Leopold, Jr., 231 

Gold in sea, 129 

Goldmark, Peter C., 201 

Goldsmith, A. N., 241 

Goodrich, B. F., Company, 45, 55, 66 

Goodspeed, T. Harper, 61 

Goodyear, Charles, 59 

Goodyear Tire and Rubber Co., 66 

Gordon, N. T., 217 

Grandpa's Knob, 272 

Grid, in electronic tube, 173 

Grijns, Gerritt, 94 

Guayule, 62 

Guncotton, 15, 36 

Gun perforator, 21 

Haber, Fritz, 13 
Haber process, 8 

Half-life of radioactive element, 263 
Hall, C. E., 227 
Hall, Charles M., 113 
Hall, Chester Moor, 148 
Hallwachs, W., 176 
Hard rubber, 38 
Harker, David, 186 
Harris, Milton, 57 
Hart, Deryl, 222 
Hartford Electric Light Co., 270 
Harvey, E. Newton, 224 
Haskell Laboratory of Industrial Toxi- 
cology, 107 
Haynes, Ellwood, 119 
Heat-prostration and Vitamin C, 105 
Heat stroke, 107 
Heavy hydrogen, 258 
Helicopter, 157 
Helium, 22 
Hemicelluloses, 79 
Henry, Joseph, 1 
Heptane, 30 

Hercules Powder Co., 18 
Heroult, Paul L. T., 113 
Herty, Charles H., 80 
Hertz, Heinrich, 168, 176 
Hertzian waves, 168 
Heterodyne circuit, 188 
Hevea brasiliensis, 60 
Hewitt, Peter Cooper, 216 
Hewlett, C. W., 152 
Hickman, Kenneth D., 3 
High explosives, 16 

Hippocrates, 92 

Hixson, Arthur W., 115 

Homer, Howard J., 153 

Honda, 124 

Hooke, Robert, 48 

Hottel, Hoyt C., 276 

Hottest flame, 6 

Howe, Goodwin H., 125 

Howe, Harrison E., 80 

Hull, A. W., 165 

Hwangti, 92 

Hyatt, John Wesley, 36 

Hycar, 66, 287 

Hydrocarbon Chemical and Rubber 

Co., 66 

Hydroforming, 33 
Hydrogen, 5 
heavy, 258 
Hydrogenation, 8, 27 
Hydrolysis, 10 
Hydroxyl, 36 

Illinois, University of, 265 

Image, photographic, 227 

Incendiary bombs, 116 

Indiana and Michigan Electric Co., 


Indigo, 62 

Induction electron accelerator, 265 
Infrared light, 163 
Inositol, 109 

Institute of Aeronautical Sciences, 163 
International Rubber Co., 62 
Iron, 117 

Irradiation of foods, 221 
Isobutylene, 287 
Iso-octane, 30 
Isoprene, 62, 285 
Isotopes, 258 

Ives, Frederic E., 229, 243 
Ives, Herbert E., 243 

Jansen, B. C. P., 98 
Jena, University of, 149 
Jenkins, C. Francis, 37, 195 
Joliot, Frederick, 265 
Jones, Frank L., 153 

KDKA, 187 

Kennelly-Heaviside layer, 205 
Kenotron, 176 
Kerosene, 24 



Kerr cell, 199 

Kerst, Donald W., 265 

Kettering, Charles F., 28 

Kinemacolor, 201 

King, Charles G., 105 

King, Edgar L., 85 

Kingdon, K. H., 283 

Klystron, 165 

Knock in automobile engine, 28 

Kodachrome, 231 

Kodacolor, 234 

Kodak, 37 

Kodak Research Laboratory, 227, 231 

Kodapak, 50 

Kodatron speedlamp, 236 

Koroseal, 45, 55, 68, 288 

Krupp Works, 118 

Lamp, carbon-dioxide, 216 

electric, 211 

Mazda, 139 

mercury, 217 

photoflash, 235 

sodium, 223 

tantalum, 212 

tungsten, 212 
Lane-Wells, Inc., 21 
Langley, Samuel P., 155 
Langmuir, Irving, 3, 174, 213 
Lanital, 50, 73 
Large-screen television, 199 
Laue, Max von, 180 
Lavoisier, Antoine Laurent, 6 
Lawrence, Ernest O., 260 
Lead azide, 17 
Lefad, Jim, 121 
Lenard, Philip, 168 
Libby-Owens-Ford Glass Co., 143 
Light, "black," 120 

chemical, 224 

cold, 224 

infrared, 163 

polarized, 242 
Lightning, artificial, 2 
Lignin, 78 
"Lime-juicer," 93 
Linear accelerator, 260 
Long-distance telephony, 203 
Long, Perrin H., 85 
Lucite, 43, 57 
Lumarith, 37 
Lumen, 210 

Lunin, N., 93 
Lustron, 46 
Lyman, Joseph, 166 

Macready, J. A., 162 
Magnesium, 116 

from sea water, 132 
Magnetron, 165 
Magnets, 123-128 
Maltase, 9 
Manganese, 119 
Mannes, Leopold D., 231 
Marconi, Guglielmo, 187 
Martin, Gustav J., 109 
Mason, William H., 77 
Masonite, 77 
Massachusetts Institute of Technology, 

152, 236, 275 
Maurer, Eduard, 118 
May and Baker, Ltd., 88 
Mazda lamp, 139 

efficiency of, 215 
McCutcheon, Don M., 182 
Mees, C. E. K., 233 
Mellon Institute, 2, 81, 143, 153 
Merck and Co., 89, 98 
Mercury fulminate, 17 
Mercury- vapor lamp, 216 
Metallurgy, powder, 122 
Meteorites, 112 
Methane, 24, 31 
Methyl rubber, 63, 285 
Metropolitan Opera House, 254 
Microfilm, 238 
Microscope, 147 

electron, 184 
Microwaves, 165 
Midgley, Thomas E., Jr., 29 
Milk, as raw material, 70 

paint from, 72 

Millbank Memorial Fund, 107 
Millers National Federation, 100 
Mine Safety Appliances Co., 19 
Molding powder, 38 
Molecules, large, 39 

water, 5 

Molybdenum, 120 
Monsanto Chemical Co., 46, 143 
Moore, C. N., 152 
Moore, D. McFarlan, 216 
Morey, George W., 149 
Moss, Sanford A., 160, 271 



Moth-resistant wool, 58 
Motion pictures, sound, 239 

stereoscopic, 242 
Muscle tone, 107 

Napoleon III, 113 

National Broadcasting Co., 200 

National Bureau of Standards, 57, 115, 


National Dairy Products Corp., 71 
National Research Council, 101 
Neoprene, 64, 286 
Network television, 203 
Newton, Isaac, 148 
New York World's Fair, 242 
Niacin, 104 

Niagara Falls, power from, 271 
Nicoll, F. H., 153 
Nicotinic acid, 104 
Nier, Alfred O., 283 
Nieuwland, Julius A., 64 
Night vision, 102 
Nitration, 36 
Nitrocellulose, 15 
Nitrogen, atmospheric, 13 

dioxide, 13 

in lamps, 214 
Nitroglycerine, 15 
Nobel, Alfred, 12 
Noctovision, 195 
Notre Dame, University of, 64 
Nuts, chemurgic uses of, 82 
Nylon, 3, 54 

Oberlin College, 113 
Obsidian, 136 
Octane number, 30 

effect on airplane performance, 32 
Oersted, Hans Christian, 113 
Oil refining, 26-28 
Optical glass, 147 
Otlimer, Donald F., 80 
Overtones, 193 

Owens-Corning Fiberglas Corp., 145 
Oxalic acid, 80 
Oxygen, 5-7 

Pacific Gas and Electric Co., 269 
Panchromatic emulsions, 228 
Panoramic sight, 151 
Pantothenic acid, 95 
and gray hair, 109 

Papain, 10 

Para-aminobenzoic acid, 109 
Paraffin, 25 

Parsons, Sir Charles, 268 
Passamaquoddy, 273 
Pasteur, Louis, 48 
Peanuts, 82 
Pearl Harbor, 166 

use of sulfa drugs at, 85 
Pellagra, 93 
Pentane, 24 
Perbunan, 66, 287 
Perforator for oil well, 21 
Periscope, 152 
Permalloy, 207 
Perminvar, 207 
Petterssen, Sverre, 163 
Phagocytes, 90 
Philadelphia Orchestra, 244 
Phosphorescence, 198, 216 
Phosphors, 216 
Phosphorus, radioactive, 263 
Photoelectric cell, 176 
Photoelectrons, 177 
Photoflash lamp, 235 
Photographic image, 227 
Photography, 226 

color, 228, 234 
Photosynthesis, 279 
Photovoltaic cell, 178, 274 
Picric acid, 16 

Pittsburgh Corning Corp., 144 
Pittsburgh Plate Glass Co., 143, 150 
Pittsburgh, University of, 105 
Planck, Max, 177 
Plastic airplanes, 42 
Plastics, 35 

bearings of, 40 

formaldehyde in, 38 

thermosetting, 35 

urea-formaldehyde, 41 

vinyl, 56 

Platinum, spongy, 9 
Play-backs, 239 
Plexiglas, 43, 57 
Plywood, 41 
Pneumonia, 90 
Polarized light, 242 
Polaroid, 242 
Pollock, H. C., 283 
Polyamides, 58 
Polyhexamethylene adipamide, 58 



Polymerization, 27 
Polymers, 36 
Polystyrene, 46 
Poulsen, Valdemar, 251 
Powder, black, 15 

flash, 235 

smokeless, 16 
Power, sources of, 267 

sun, 274 

thermocouple, 277 

tides, 273 

wind, 272 
Priestley, Joseph, 6 
Prontosil, 87 
Propane, 24 
Prothrombin, 102 
Protons, 257 
Ptyalin, 9 
Public Service Gas and Electric Co., 


Purdue University, 164 
Pyralin, 37 
Pyrex glass, 140 
Pyridoxin, 95 
Pyroxylin, 36 

Quartz, 140 

Rabbit brush, 61 

Rabinovitch, Eugene, 280 

Radiation Laboratory, Univ. of Calif., 

Radio, 187 

links for television, 205 

transmission, 175 
Radioactivity, artificial, 263 
Radio Corporation of America, 153, 

164, 196, 205, 245 
Radiographs, 182 
Ravdin, I. H., 85 
Rayon, 49 

acetate, 37 
Reaumur, R. A., 48 
Recordak, 238 
Refraction, 147 
Regenerative circuit, 188 
Resins, 39 

acrylic, 43 

alkyd, 45 

phenolic, 40 

vinyl, 44 
Research Corp., 247 

Riboflavin, 95, 103 

Rickets, 93 

Riggs, L. K., 71 

Rivets, explosive, 19 

Rockefeller Foundation, 247 

Rockefeller Institute, 109 

Roentgen, Wilhelm Konrad, 168 

Rohm, Otto, 43 

Rosin, 35 

Royal Danish Academy of Sciences, 

Rubber, 59-63 

buna, 66, 286 

butyl, 37, 288 

elasticity of, 63 

guayule, 62 

hard, 38, 67 

methyl, 63, 285 

plantations, 60 

structure of, 285 
Rutherford, Sir Ernest, 256-257 

Safety glass, 142 
Saltpeter, 12 
Saturation, 67 
Scanning disc, 195 
Schaefer, Vincent J., 186 
Scheelite, 120 
Schmidt, Bernard, 200 
Schmidt camera, 237 
Schoen, A. L., 227 
Schott Glass Works, 149 
Schroeder, R. W., 161 
Schwarz, Berthold, 15 
Scurvy, 92 
Sea water, 129 
Sebrell, William H., Jr., 100 
Second Sound Show, 248 
Self-starter, 28 
Semon, Waldo L., 66 
Sextant, 151 
Shapley, Harlow, 237 
Shear disc, 22 
Shellac, 35 
Sherr, Rubby, 262 
Shrunken glass, 141 
Sight, panoramic, 151 
Signal Corps, U. S. Army, 188 
Sikorsky, Igor, 158 
Silk, artificial, 48 

U. S. consumption of, 50 
Silver bromide, 227 



Single-shot color camera, 231 
Sintering, 122 
Slayter, Games, 145 
Smith, D. Stanley, 241 
Smithsonian Institution, 275 
Smokeless powder, 16 
Sobrero, Ascanio, 15 
Sodium lamp, 223 
Solar energy, 281 
Sonovox, 249 
Sound control, 248 
Sovprene, 66, 286 
Soy bean, 50, 74 

protein fiber, 75 
Space charge, 174 
Spectroscope, 147 
Spencer Lens Co., 150 
Sperry Gyroscope Co., 166 
Spies, Tom D., 104 
Spirakore transformer, 128 
Spontaneous combustion, 6 
Sporn, Philip, 269 
Standard Oil Co. of Indiana, 25 
Standard Oil Co. of New Jersey, 27, 


Stanford University, 165 
Staphylococcus, 86 
Starch, 76 
Static, 190 
Steel, stainless, 117 
Steenbock, Harry, 108, 221 
Stellar energy, 282 
Stellite, 119 

Stereophonic sound transmission, 244 
Sterols, 107 

Stevens Institute of Technology, 246 
Stine, C. M. A., 51 
Stockings, runless, 55 
Strauss, Benno, 118 
Streptococcus, 86 
Streptozon, 86 
Strong, John, 152 
Styrene, 46, 286 
Styron, 46 

Subtractive color mixture, 229 
Sugars, wood, 78 
Sulfadiazine, 88 
Sulfaguanadine, 88 
Sulfanilamide, 86 
Sulfapyridine, 88 
Sulfathiazole, 88 
Sulfuric acid, 8 

Sullivan, Eugene C., 154 
Superheterodyne circuit, 188 
Synthea, 254 

Synthesis of natural products, 62 
Szent-Gyorgi, Albert von, 105 

Talbot, William Henry Fox, 226 
Tantalum lamp, 212 
Taylor, H. D., 152 
Technicolor, 240 
Telegraphone, 251 
Telephone cable, 207 
Telescope, infrared, 164 

200-inch, 179 
Television, 194 

color, 201 

large-screen, 199 

network, 203 
Tempered glass, 142 
"Tenderizing" of meat, 10 
Tenite, 37 

Terrain distance indicator, 167 
Tetraethyl lead, 29 
Textile Foundation, 57 
Texolite, 40 
Thermit, 116 

Thermocouple, as power source, 277 
Thermoelectric effect, 277 
Thermoplastics, 35 
Thermosetting plastics, 35 
Thiamin, 97, 103 
Thioglycollic acid, 57 
Thiokol, 288 
Thomas, John H., 145 
Thomson, G. P., 184 
Thomson, Sir J. J., 170, 256 
Thunder screen, 252 
Thyratron, 176 
Tidal power, 267, 273 
TNT, 17 
Toluene, 33 
Tracer elements, 264 
Transatlantic telephony, 206 
Transformers, 126 
Translators, FM, 191 
Transmutation, 11 
Trinitrotoluene, 17 
Triode, 173 
Tripack, 231 
Triplex glass, 143 
Triptane, 31 
Trollhattan, 272 



Tungsten, 119 

ductile, 213 

lamps, 212 
Turbines, 268, 271 
Turbosupercharger, 160, 271 

Ultraviolet irradiation of foods, 221 
United Air Lines, 167 
United States Steel Corp., 118 
Unsaturation, 67 
Uranium, 235, 283 

fission, 282 

Urea-formaldehyde plastics, 41 
Urey, Harold C., 258 

Valence, 67 

Van de Graaff generator, 259 

Vanillin, 79 

Varian, Sigurd and Russell, 165 

Vedder, Edward B., 97 

Velocity power tools, 19 

Velox, 38 

Vinylite, 45 

Vinyl plastics, in wearing apparel, 56 

Vinyl resins, 44 

Vinyon, 45, 51 

Viosterol, 108 

Viscose process, 49 

Vistanex, 288 

Vitamin A, 94, 102 

Vitamin B, 94 

Vitamin Bi, 98-103 

Vitamin B 2 , 103 

Vitamin C, 94, 105 

Vitamin D, 107, 221 

Vitamin E, 101 

Vitamin G, 95, 103 

Vitamin H, 96 

Vitamin K, 101 

Vitamin P-P, 104 

Vitamins, 92 

essential, 102 
Vitaphone, 239 
Vocoder, 249 
Voder, 249 
Vulcanite, 38, 67 
Vulcanization, 67 

of rubber, 60 

W57A, 190 

Walnuts, chemurgic uses for, 82 
Warner Institute for Therapeutic Re- 
search, 109 
Water power, 267 
Waves, Hertzian, 168 
Weaver, W. L., 106 
Webb, B. H., 74 
Weidlein, Edward R., 143 
Weir, I. R., 192 
Wells, M. W., 222 
Wells, W. F., 222 
Westendorp, Willem F., 181 
Westinghouse Electric and Mfg. Co., 

165, 187, 219, 222 
WGY, 189 

Science Forum, 247 
Whey, 74 
"Wheyfers," 74 
Whitby, L. E. H, 88 
Whitney, Willis R., 127, 212 
Whole-wheat flour, 101 
Wilder, Russell M., 100 
Williams, Greville, 62 
Williams, Robert R., 97, 102, 109 
Williams, Roger J., 7, 95 
Wilm, Alfred, 115 
Wimperis, H. E., 155 
Wind power, 272 
Wisansky, W. A., 110 
Wisconsin, University of, 95, 108, 221 
Wohler, Friedrich, 113 
Wollaston, William H., 123 
Wood, John, 142 
Wood sugars, 78 
Wooley, D. W., 109 
WRGB, 205 
Wright Brothers, 155 
Wright, Gilbert M., 249 
Wiirzburg, University of, 168 

X-rays, 169-170, 179-183 
X-ray tubes, multi-stage, 181 

Yale University, 279 
Yarn, alkylation of, 57-58 

Zein, 76 

Zeiss, Carl, 149 

Zworykin, V. K., 164, 184-186, 196 

Concerning the Author 

JAMES STOKLEY was born in Philadelphia on May 19, 
1900. He pursued his undergraduate and graduate 
studies in biology and psychology at the University 
of Pennsylvania; and since 1925, following a period as 
a teacher in the Philadelphia Central High School, he 
has devoted himself to making available to a wider 
audience the specialized findings of scientific labora- 
tories here and abroad. In 1931, after six years as staff 
writer with Science Service, Inc., in Washington, D.C., 
Mr. Stokley became associate director, in charge of 
astronomy, at the museum of the Franklin Institute in 
Philadelphia, where also he had charge of the pho- 
tographic and seismographic sections. When the In- 
stitute's Fels Planetarium opened in 1933 he was its 
first director, continuing in his lectures there an in- 
terest which he had formed when studying the opera- 
tion of the two original planetaria at Jena and Munich. 
His earlier book, Stars and Telescopes, gives a popular 
account of the studies of astronomers. His work in 
Philadelphia led to his appointment in 1939 as director 
of the Buhl Planetarium and Institute of Popular 
Science at Pittsburgh, and latterly as editor in physical 
sciences with Science Service, Inc. Since 1941 he has 
been associated with the General Electric Research 
Laboratory at Schenectady. In his preparation of 
had access to many of the latest developments 
in the major university and industrial 
laboratories of the United States. 



James Stokley is a man "whose head is in 
science while his heart is among the people." 
He is Technical Book Editor of the New York 
Herald Tribune, and co-ordinator of scien- 
tific information for one of our largest in- 
dustrial concerns. 

He was formerly a director of the famous 
Franklin Institute in Philadelphia, and of the 
Institute of Popular Science in Pittsburgh; 
he was also a member of the editorial staff 
of Science Service, Inc. in Washington. 

In the preparation of SCIENCE REMAKES 
OUR WORLD, Mr. Stokley has had access 
to the latest findings in the research world. 


"A simple, clear, comprehensive report of 
what is going on in the laboratories now, of 
what is on the horizon for all of us ... Mr. 
Stokley's discussion is balanced and authori- 
tative, lucid and stimulating. It neatly lives 
up to its title with a social, not a technical 
or propaganda point of view." Dr. Gerald 
Wendt in N. Y. Herald Tribune BOOKS. 

"This is the best book of its kind." Dr. Har- 
rison W. Craver. 


"The average book on science and what it 
does and can do leaves me as cold as a 
mackerel. But somehow this book has a way 
with it, a way that will snag the interest of 
most of those who look upon science as a 
dull, vastly important thing that they are 
content to leave in the laboratories with the 
scientists. . . . The best book of its kind I ever 
saw." From a review in the Springfield 
(Mass.) Union. 


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