When Zworykin returned from his 1939 trip, he found that the war in Europe had not yet affected life in the United States. The work at the RCA Laboratories proceeded as before, but some projects began to achieve priority over others, and gradually over the next year, the research work began to be involved almost completely with military problems.

One of these problems was seeing in darkness. We already had such devices as the electronic image tube, which was sensitive to infrared light, so we started to adapt it for the purpose of driving at night without visible lights or firing guns at night. (During this time we developed the "snooperscope" and the "sniper-scope", practical applications of our research on infrared image tubes.) In testing night driving without light on New Jersey roads, we were stopped several times by local police who thought we were spies, so we had to obtain a special permit for this purpose. We also gave a successful demonstration of night tank driving to General Patton in a camp in the south where his armored division was training. Eventually, it was accepted by the armed forces. The [Army] Air Force began to be interested in a controllable flying bomb with television sights in a project we started under the name "Rock." Of course, all this work now became a military secret. When the United States entered war, all these activities were greatly accelerated. I was made a member of Dr. [Theodore] Von Kármán’ s Advisory Committee to the Air Force and served in this capacity for the duration of the war.

Meantime, the new RCA Laboratory was completed in Princeton and in 1941 we moved into the new building. This was a vast improvement compared to our improvised quarters in Camden. For me, personally, it meant abandoning the house I had built at Taunton Lakes near Camden, New Jersey, and moving into another house in Princeton.

Although for the duration of World War II and even for some time after, all our efforts were concentrated on military projects, the character of the work in laboratory changed little, remaining in the electro-optical field. The biggest achievement of this period was the development of the image orthicon pickup television tube, a combination of Iconoscope with image tube and multiplier. It was originally built for military use of television on air­planes but eventually was adapted to broadcasting television. (p. 109)

Another development brought to final implementation during the early war years, was the electron microscope, which became a production item and eventually an indispensable tool in many laboratories

In the mid-1930s, on one of my European trips, I visited a laboratory in Germany where I found preliminary work being done on the electron microscope. When I returned to the United States, I began working on the development of an electron micro­scope in our own laboratory. The first model we constructed, of course, had a shape much different from those available now; this model was essentially a modification of television. We planned to use a beam instead of reproducing the picture; we let it strike a specimen by a large color chemical specimen and then reproduce it on the kinescope receiver. (At the present time we call this the scanning electron microscope.) However, our original form did not look very promising because we could not get much improvement in magnification and resolution and this was soon abandoned in preference of an extended image [transmission] electron microscope. Here the electron beam, after passing the electron transparent specimen, was passed through the magnifying electromagnetic screen and was expanded in very large image. That way at the very beginning we succeeded in magnification and resolution much greater than is possible with an ordinary light microscope. We also began to learn that in other countries the work in this direction was progressing satisfactorily and looking to enlarge the group which was suitable for this work we found in Toronto, Canada, work was going on in the same field and we succeeded in bringing to our laboratory one of the young engineers who was working with them, Dr. James Hillier. Jim proved to be a very valuable man and he developed the first practical commercial electron microscope to be manufactured in the United States.

There was great skepticism in the RCA commercial department about the possibility of a large market for the electron micro­scope. Our first evaluation of the American market, for instance, by a very reputable company, stated that only six instruments would be sold throughout the entire United States. Actually, thousands of electron microscopes are now already in use in this country alone, and it is actually one of the most important tools practically in every laboratory.

In 1943, I was elected to the National Academy of Science which was a great honor. About this period I was asked by some members of the Russian War Relief to accept the chair­manship of their New York Chapter. My first reaction was negative since from my first days in the United States I stayed out of the political arguments of the Russian emigré colony and furthermore was too busy in the laboratory to do any outside work. However, they pointed out that this was the very reason they chose me since I was acceptable as a neutral to all political shades of the colony. Further­more, the main purpose of the Russian Relief was to collect clothing and funds to be sent to Russia (our ally), where there was great suffering from the German invasion. In (p. 110) addition, they pointed out that among the members was Mrs. Eleanor Roosevelt, with the president, and Henry Wallace, the vice-president. I finally agreed to accept the chairmanship of the New York chapter on the condition that it would be in name only and I would not be asked to give my time since I was too busy with my work. I did not realize that I would have to pay dearly for this acceptance.

When the Germans surrendered, Dr. Von Kármán organized a group of specialists to go to Europe to study German technological advances, and I was chosen to be one of them.  This required considerable preparation, even a special uniform had to he ordered. When I reported to the airport in Washington to board the plane, I was told that my passport was not ready so I could not go with the group. All my efforts to find out when I would I leave the passport or the reason why it was not ready were to no avail. Finally, I was told that my passport was denied by the State Department on account of my being a member of the Russian War Relief. Since the organization was a legal one, and included such prominent persons, as I mentioned before, tile only reason that I could see for this was my Russian origin. This was a bitter pill to swallow after so many years and many contributions to my new country. I felt like I was confined in a cage again. I resigned from Van Kármán’s committee and planned to resign from RCA because of my work on secret projects for which under the circumstances I could not be cleared; but General [David] Sarnoff talked me out of it, and promised the help of the RCA Legal Department to fight for me. Finally, in 1947, my passport was restored and I began to feel like a free man again.

 Shortly after the war at a time when some destructive hurricanes struck the East Coast, Dr. Zworykin conceived the idea that it should be possible to divert hurricanes with possibly a small expenditure of power at the time when the hurricane was in its formation stage. He discussed this problem with Dr. John Von Neumann, of the Institute for Advanced Study at Princeton. Out of such discussions grew the concept of the electronic computer for weather prediction, since it soon became apparent that the mathematics were too involved to handle in any other fashion. (p. 111)