5/14/35 - Today Dr. Lucy Hayner and Professor Kurrelmeyer of Columbia University, called on us. I described the general nature of the work done in the laboratory and took them through the factory. Dr. Shaw took them through the Chemical Section, and showed pictures of the bariated emission surfaces taken by Nelson on the electron microscope. I took them through our laboratory and Harry Thompson explained some of his work on beam tubes, and Dr. North and I discussed with them the work on shot effect. I explained in rather elementary manner our disagreement with Llewellyn's thermal agitation formula, and my- own derivation of the shot effect in the presence of space charge.

Yesterday Mr. Ritter told me that he had discussed with Mr. Warner our plans for the new exhaust system, and he felt that there would be no hold up.

I discussed yesterday with Mr. Ritter the need of space and apparatus for [Harley F.] lams' work on iconoscopes, and he agreed that if [Harley] lams could get along for the beginning with the present iconoscope test apparatus, more generalized equipment could be supplied later as needed, and when justified. He asked me to get in touch with [D. F.?] Schmit about the possibility of our using the room in building II, second floor, and moving up the iconoscope test equipment from the basement to that room. I discussed today with lams these matters, and he is in general agreement that it will be satisfactory for him to divide time with the Development Section on the present iconoscope equipment, and that this can be done wherever necessary, but desirably in the room on the second floor. I discussed with lams the matter of his being relieved of his present activities as rapidly as possible.

5/15/35 - Today R. A. Hampshire began work in our section, and John Becker was transferred from the factory to our section for work on the exhaust system.

5/22/35 - Yesterday Mr. Bitter informed me that there is an increased demand for a projection tube for television use. It is now planned to have a transmitter on the air within ten months, and within a year at the most some sort of projection tube should be available. He asked me to get in touch with Schmit and Shaw to arrange a coordination group on television tubes. I told him that there was already such a group, though it had not met in some time. He asked me to see these men to arrange the meetings in the future to insure personal cooperation in carrying on the work. I told him something of the work that Law has been doing, and showed him [Harold] Law’s Apparatus.

Today David Langmuir called on me, and I explained to him the general problem on which he will be working when he first comes; that of positive-ion emission from cathodes, and outlined the broader aspects of television which may be his problem in the future. He informs me that he will be taking a trip to Europe in June, and would like to report for work on September 15^th, to give him adequate time for his trip. I told him that this would be all right, and mentioned it to Mr. Ritter, who also approved it. I discussed with Mr. Ritter and Dr. Shackelford the matter of arranging introductions to our various associated companies in Europe for Mr. Langmuir, so that he will be able to take advantage of the trip to acquaint himself with the workers, and the work being done in Europe. Mr. Ritter said he felt that this would be feasible. Dr. Shackelford said that it might be necessary to take Langmuir on the payroll, and then grant him a leave of absence, for him to furnish the necessary credentials. Through Dr. Shackelford, Mr. Langmuir met two of the men from the German Osram Company. They expressed pleasure at the prospect of Langmuir's visit there, and told him to be sure to let them know when he was coming.

(p. 114) Mr. Schmit called me today in connection with a paper on cathode-ray-tube nomenclature and testing, which has been proposed for publication in the Proceedings of the I.R.E., perhaps to be written by Perkins. I told Schmit something of the work of the Cathode-Ray Tube Subcommittee of the Technical Committee on Electronics, and offered to go over the subject with Perkins so that he would be able to make use of any of the recommendations of the Subcommittee which he saw fit to use, in this way it being possible for the Subcommittee to make the best use of Perkins' material. Schmit agreed to this, and said that he would have Perkins get in touch with me.

5/27/35 - This afternoon I discussed with Mr. Ritter, at his invitation, the possible arrangements for increased effort on the projection-tube work. Mr. Ritter states that there will be approximately ten months in which to have a satisfactory projection tube, and that it will require a considerable amount of research, in his opinion. I outlined tentatively the changes we could make, which are very few at the present time, and within the scope of our present organization. I shall discuss this matter with Law and continue the discussion with Ritter tomorrow. I pointed out the possible desirability of increasing our number of technical assistants rather than attempting to get all the work done by research workers.

I discussed [Dwight O.] North's paper with Dr. Shackelford today telling him of the deletion of the reference to the “Cyclone," but of the retention of the reference to the negative-resistance temperature-limited diode. Dr. Shackelford said he did not think it would be necessary to file an application on this before the paper is released.

6/14/35 - I discussed with Zworykin and Morton the matter of projection tubes. Zworykin suggested that cando-luminescence might be feasible if some good insulator under the luminescent material could be found. He tested asbestos velvet with the luminescent material on the end of the fibers. He said that he had attempted to get such a velvet, but has been unable to do so. He felt that perhaps we would be able to get it here. I said that I would consider it. I discussed with Zworykin our ideas on light valves using the critical angle of reflection as a means of modulating the light, and pointed out the need for some material with a variable index of refraction. During the discussion I had an idea for a light valve in which some finely divided dielectric material in disc form would be suspended in a fluid of differing dielectric constant. It would appear that if en electrostatic field were applied through the liquid, the discs of dielectric material would orient themselves in the field thus decreasing the light absorption of the material, and that if the field were removed the Brownian motion would cause the particles to orient themselves at random. This seems feasible to me. Zworykin showed me his ionization gauge amplifier which he says is very convenient.

Dr. Lucy Hayner visited me today and discussed with me her paper on fluctuation noise due to secondary emission. She left a copy of this paper with me. I told her a little of the work that has been done along this line here in our laboratory. I offered to try to supply some of the special tubes she needs for her work.

[Harold] Beverage and Comings of RCA Communications visited our laboratory today, and I showed them the work that Kilgore is doing on magnetrons.

(p. 115) 7/9/35 - Today Mr. D. F. Schmit came in to see me in connection with the getter problems on one of the metal tubes. They are having a great deal of trouble with gas on these tubes, and are seeking some better method for exhausting them. I discussed with Mr. Schmit my observations on the effect of glow discharge in the tube during exhaust on the vacuum obtained after exhaust, and I suggested that the equivalent of this could be obtained by having a discharge between plate and metal shell during exhaust. I discussed this also with Mr. J. M. Smith who showed a great deal of interest in it, and as a result with some of the factory engineers. They are anxious to try the idea out, end asked for definite recommendations. Therefore, I obtained ten tubes from Dickinson in the factory, and intend to try out the voltage and current conditions which will produce a discharge between plate and metal shell under exhaust conditions. It is my idea that the inside of the shell should be cleaned off by the discharge process and maintained at a zero or negative potential during operation of the tube.

7/12/35 - I tried out some of the metal tubes on our exhaust outfit, and find that it is difficult to obtain a glow discharge between metal shell and the other electrodes of the tube at 150 to 300 volts potential unless the cathode is heated and is emitting electrons. Therefore, I suggested to Dickinson yesterday that conditions of exhaust which might be tried out were as follows: cathode and shell connected together, other electrodes at 150 to 300 volts positive through a 10-watt lamp. Dickinson said he would try this out.

7/25/35 - Today Drs. Wolff and Linder, and Mr. Braden came to discuss matters with our short-wave group, and look over the work they are doing. Each man in the group showed them his set-up and explained his work. Kilgore showed his tube for observing the paths of the electrons in magnetrons. I discussed this with Dr. Wolff and explained my theories on the mechanism of oscillation of negative-resistance oscillators, Posthumous-type oscillators, and electronic-oscillators. Several tubes were given to Dr. Wolff and his men.

Dr. [Henry] Kozanowski was here today to inquire about the prospects for a position. I interviewed him and introduced him to Mr. Ritter, and had him talk to Headrick, Spitzer, and James. It was explained to Dr. Kozanowski that we could not make him an offer if he was still considering the offer made to him by RCA Victor.

I also interviewed Dr. R. F. Clash today. He was introduced to Mr. Ritter and interviewed by Dr. Headrick. Dr. North took him through the factory. I suggested that he have his professors at Yale send us recommendations concerning him.

8/5/35 - Today, at Mr. Warner’s request, I showed Mr. [Lewis] Clement, [vice-president] of RCA Victor, through our laboratory, explaining the work we are doing. I showed him some of the beam-tube work, the input-loading work. Kilgore’s work on magnetrons. Law’s special cathode-ray tube, and the set-ups in the cages used by North, DeVore, and Nergaard. I also showed him the field-plot tank and the machine shop.

I discussed with Stinchfield organization plans for the work on projection tubes, and found that he is favorably inclined toward taking additional responsibility.

8/8/35 - Today I explained to Mr. Ritter the study of electron-beam paths which Kilgore is making in a model of a magnetron. Kilgore demonstrated his equipment. I described our present record system in some detail to Mr. Ritter.

(p. 116) 8/13/35 - Professor John Tate, of the University of Minnesota, visited our laboratory. He showed him something of the work that Kilgore is doing: and also showed him the tube of Dr. Law's, and the set-up of Dr. North's and Mr. Nergaard's. I discussed the filament-bombardment effect which Kilgore has observed with Professor Tate, and explained to him my theory of the closed vessel.

9/13/35 - On Monday, September 9th, Messrs. Metcalf, Glass, Kievet, DuMont, Blackburn, and Westman, comprising the I.R.E. Subcommittee on cathode-ray tubes, met in my office from 1 until 8:15 p.m.

On Wednesday, September 11^th, Mr. Cosgrove, of the E.M.I. Company, visited our Section, and I discussed with him the work we are doing, particularly on short waves.

Today Mr. van Gessel, of the Phillips Company, visited us, and I discussed our work on input loading, beam tubes, and power-outlet tubes. I mentioned the single-stage multiplier tube as a means for cutting down input loading.

I discussed with Stinchfield today his need for a dark room. He agreed that temporarily, at least, he should be able to get along with the facilities in the Cathode-Ray Laboratory.

9/16/35 - Messrs. [Stuart W.] Seeley and Barden, of the RCA License Laboratory, called on Dr. North and me to discuss the measurements of noise in vacuum tubes which they have been making. I offered a suggestion as to the possible cause for their strange results, the explanation being based on an inconstant division between screen and plate current.

Dr. Zworykin called on me to discuss his plans to visit us each Monday in connection with the television work. I assured him that we would be glad to cooperate.

9/23/35 - Today I saw Dr. Zworykin, accidentally, at lunch. He told me that he would be in to see me, and I told him that I would be glad to see him and would be in at any time he came. I heard nothing further from him.

Mr. Charles Banca, of Victor, spent about an hour with me this afternoon discussing iconoscopes in general, and the dark spot in particular. Banca outlined his theory of dark-spot production, and I pointed out to him what he appeared to agree was a serious objection to his theory. I had a considerable discussion this afternoon with Clark, at his request, concerning his work.

9/30/35 - Today I saw George Morton, of Victor, in our laboratory talking to Kilgore. Later I had a considerable discussion with him concerning his calculations on measurements of noise from secondary emission. Dr. Zworykin, so I understand, was here but did not call on me.

I discussed in general terms with John King our need for help on cathode-ray-tube mounting. He promised to call on me with Kirschner to discuss the matter.

(p. 117) I called Farese today concerning Majorie Murphy to make arrangements for her corrected hourly rate. I attempted to call Mr. Ritter in this connection also.