Discussion of "A History of Some Foundations of Modern Radio-Electronics Technology" Page 1264

ternal to the Fleming valve, where he may have meant a grid within the valve.

23) Critique. “The strange thing is that it was not followed up.”

Rebuttal. Our conjectures as to why the work was dropped by Lowenstein are stated in the paper. Lowenstein’s research was made available to the General Electric Company,²⁸ with more facilities and competence than Hammond-Lowenstein for carrying out “a systematic investigation of the influence of the vacuum.” Dr. G. W. Pierce once recalled to us, “We were not at all sure there was any great future for the triode tube, but felt that any future lay in the development of the hard tube.” The hard tube was a General Electric development.

24) Critique. “And it is singular that to Hammond, ‘The exact nature of the ionic devices and the manner of operation are not known’.”

Comment. The technical details may be in the Lowenstein files concerning which our inquiries have been futile. There is a suggestion of a method of regeneration in the book, critic’s reference 27, in the figure of a detector circuit for which unusual sensitivity was claimed. (See Fig. 77, p. 133.)

25) Critique. “One wonders . . . that the evidence of . . . an oscillation generator . . . was not presented to the courts.”

Rebuttal. There is a statement of the oscillatory use of triodes in the book, critic’s reference 27. (See p. 179.)

26) Critique. “. . . the letter which Hammond wrote the President of that company. . . .”

Comment. This action proves, if nothing more, the Hammond objective of getting radio-electronics on a foundation free from foreign domination. It also discredits the critic’s view that all of Hammond’s work was conducted in secret.

27) Critique. “. . . a copy of the letters was sent to him. . . .”

Comment. We wish to make it clear that the letters were not given to our critic for that purpose.

28) Critique. “Arnold later testified . . . ‘I was very much astonished and somewhat chagrined. . . .’”

Comment. Arnold’s chagrin must have been matched later by that of our critic who had known of the superiority of the de Forest detector during two years of engineering service with the Telephone Company.

29) Critique. “There was ordered from Germany the latest type of vacuum pump.”

Comment. This is a point of important historical significance, since it shows the Telephone Company work was much later than that of the General Electric Company in the production of high vacuum tubes.

30) Critique. “. . . the company originally could have had the patent for $20,000.”

Comment. The Lowenstein patent was used by the Telephone Company in many infringement suits, and presumably made a profit even at the final figure.

31) Critique. “Actually, Lowenstein and Hammond, by coming into the picture when they did . . . performed a major service.”

Comment. Mr. Hammond, by foreign travel and contacts, realized that the growth of the “Telefunken” and other foreign companies, and their penetration into the United States, could be checked only by interesting large electrical companies in getting into the communication and equipment field. Appearing before the board of the General Electric Company for the purpose of interesting it in an American radio company, he was unable to make the progress later achieved by the efforts of the Navy Department. It is gratifying to learn that his indirect approach to the General Electric Company, the Telephone Company, and the Federal Company is getting to be accepted as a major service.

32) Critique. “It must have been in early November, 1912, that de Forest was in Gloucester.”

Rebuttal. The premise that de Forest first went to the Bell people is in error. Our documentation is a letter²⁹ and a telegram³⁰ which places de Forest in Gloucester in late October, as stated in the paper. The visit was not in connection with the amplifier work of either de Forest or Lowenstein, and the information was casually given.

33) Critique. “As if it were new, Hammond referred it to the General Electric Company as ‘the proper triode design’.”

Rebuttal. The clause “as if it were new” is unjustified. It was an engineering design, expressing the personal views of the members of the Hammond group. This design was not at first followed by the General Electric Company for the reasons stated. Nor was it followed by the Telephone Company in their first wartime type E and J tubes. The original pencil sketches, of which our critic presumably has a copy,³¹ carry two dated signatures. These are the signatures of attorneys of the General Electric Company, and not of anyone of the Hammond group. In fact, the only direct indication of the Hammond source of the design is that the material would be recognized as being in the handwriting of Dr. G. W. Pierce, then a consultant to the Hammond Laboratory. Not even he bothered to sign the sketch.

IV. MODERN INTERMEDIATE FREQUENCY CIRCUITRY

34) Critique. “In a patent interference, Hammond was awarded a claim which he interprets as giving him ‘the broad subject matter of intermediate frequency circuitry’.”

Rebuttal. Our statement rather was, “the broad subject matter in controversy was awarded Hammond.” We have very clearly stated our belief that Hammond contributed the selective features of intermediate frequency circuitry, while it was Alexanderson who, due to his development of the TRF amplification idea, contributed the sensitivity features. The withdrawal of the Lévy patent application from the interference should not be overlooked.

35) Critique. “In 1909–1911, the Telefunken. . . .”

Rebuttal. The Telefunken equipment was not pertinent to the decision in the interference, because what our critic calls a second detector was not a detector. In fact, our critic later states parenthetically: “The tone-frequency signals, instead of being rectified, could be read in headphones or on a loudspeaker.” Apparently, our critic’s subconscious mind compelled him to use the correct word “rectified” as applied to a tonal frequency signal, and it was only his conscious mind that has attempted to call that rectifier also a detector. As our critic and former advisor of attorneys of the Telephone Company well knows, subconsciously at least, the question of when a rectifier is also a detector was thoroughly discussed in the interference. Our critic gives no patent number for the Telefunken equipment. Its operation in the respect here discussed is unquestionably subservient patentwise to earlier references cited by the Telephone Company in the interference. A brief review of that case appears to be in order.

The patent claim that has been cited originated with Heising or his attorneys. It soon developed that, if patentable, Hammond would win the claim over Heising and over Lévy. Lévy withdrew. Thereupon, in accordance with usual legal procedures, the Telephone Company, in order to try for a partial victory, attempted to prove its own written claim was actually unpatentable over art prior to both Heising and Hammond. Cited, for example³² were Fessenden 727,326; Fessenden 752,894; Blondel 824,682; and Scheller (German) 208,836. The Scheller patent was cited especially to upset the claim as to “selecting a component” and the others more especially to upset the claim as to “detecting said selected component.” These efforts of the Telephone Company were unsuccessful, and would also have been unsuccessful if the well-known Telefunken equipment had also been cited. If there was anything established technically by the interference, it was that the word “detector” relates to a device involved in the finding of something hidden, and therefore a device acting upon audio-frequency currents already being indicated by headphones or a loudspeaker cannot be termed a detector. If therefore follows that the circuit preceding a second detector must contain currents of a frequency or frequencies above the audible frequency range. Our concept of intermediate-frequency circuits was clearly stated at the beginning of the section, and it is in accordance with present accepted usage.

36) Critique. “. . . the Patent Office must have overlooked prior art.”

Rebuttal. The Patent Office considered carefully, at the very top level, all the art which the experts of the Telephone Company presented. If the Telefunken equipment had been pertinent, and it was not, any failure to uncover it would not be chargeable to the Patent Office, since this was an important interference and not a usual search case involving Patent Office personnel only. The final legal decision was by three Examiners-in-Chief, paper 67, January 27, 1922. Because of the importance of the matter, the papers then went before William A. Kirman, First Assistant Commissioner, so that both parties would have the informal views of even a higher official of the Patent

²⁸ Letter of Alexanderson to Hammond, October 21, 1912.
²⁹ Hammond to Lowenstein, October 24, 1912.
³⁰ Hammond to Lowenstein, October 23, 1912.
³¹ Enclosures in letter of W. G. Gartner of the General Electric Company to Hammond, July 1, 1913.
³² Brief for Heising, U. S. Patent Office Interference 43,858, Paper No. 64; October 21, 1912.