584 BELL SYSTEM TECHNICAL JOURNAL 



15a. Roue phonique pour la regularisation du synchronisme des mouvements. Note by 

 P. la Cour in Comptes Rendus, v. 87, pp. 499-500, September 25, 1878. 



16. Report of Physical Society Meeting of March 30, 1878. Refers to Lord Rayleigh's 



impulse motor. Nature, May 23, 1878, p. 111. 



17. Nouveaux modes d'entretien des diapasons, A. and V. Guillet. Comptes Rendus, 



V. 130, pp. 1002-1004, April 9, 1900. 



18. The Emission of Electricity from Hot Bodies, O. W. Richardson. Book. Longman, 



Green and Co., London, 1916. 



19. On electric discharge between electrodes at different temperature in air and high 



vacuo, J. A. Fleming, Royal Society of London Proc, v. 47, p. 122, 1890. 



20. The Audion — A New Receiver for Wireless Telegraphy, Lee De Forest, A. I.E. E. 



Transactions, v. 25, pp. 735-779, 1906. Electrician, v. 58, pp. 216-218, 1906. 



21. Improvements in instruments for detecting and measuring alternating currents, 



J. A. Fleming. British Patent No. 24850, 1904. 



22. Device for amplifying feeble electrical currents, Lee De Forest. U. S. Patent No. 



841387, issued January, 1907. 



23. Einrichtung zur Erzeugung elektrischer Schwingungen, Siegmund Strauss. Austrian 



Patent No. 71340, filed Dec. 1912, issued June, 1915. 



24. Improvements in receivers for use in wireless telegraphy and telephony, Marconi 



Wireless Telegraph Company, Ltd. and Charles Samuel Franklin. British Patent 

 No. 13636, filed June, 1913, accepted June, 1914. 



25. Wireless Telegraph and Telephone System, Lee De Forest. U. S. Patent No. 



1.507.016, filed September, 1915, issued September, 1924, and U. S. Patent No. 



1.507.017, filed March, 1914, issued September, 1924. 



26. The use of the triode valve in maintaining the vibration of a tuning fork. W. H. 



Eccles, Phys. Soc. of London Proc, v. 31, p. 269, 1919. 



27. Sustaining the vibration of a tuning fork by a triode valve, W. H. Eccles and F. W. 



Jordan, The Electrician, v. 82, p. 704, June 20, 1919. 



28. Sur L'entretien des oscillations mechaniques au moyen des lampes a trois electrodes, 



Henri Abraham and Eugene Block, Comptes Rendus, v. 168, pp. 1197-1198, June 

 16, 1919. 



29. Electron tube drive for tuning fork, E. A. Eckhardt, J. C. Karcher, and M. Keiser, 



Physical Review, v. 17, pp. 535-536, April, 1921. 



30. An electron tube tuning fork drive, E. A. Eckhardt, J. C. Karcher and M. Keiser, 



/.0.5.^.-No. 6, pp. 949-957, November, 1922. 



31. The valve maintained tuning fork as a precision time standard, D. W. Dye, Royal 



Soc. of London Proc, v. 103, pp. 240-260, May, 1923. 



32. Frequency measurements in electrical communication, J. W. Horton, N. H. Ricker, 



W. A. Marrison, A. I. E. E. Trans., v. 42, pp. 730-741, June, 1923. 



33. A celestial encounter, Ernest William Brown, Jl. Franklin Institute, v. 202, pp. 127- 



163, August, 1926. 



34. The best observed eclipse in history. Scientific American, March, 1925, p. 155. 



35. Precision determination of frequency, J. W. Horton and W. A. Marrison, /. R. E. 



Proc, V. 16, pp. 137-154, February, 1928. 



36. The valve maintained tuning fork as a primary standard of frequency, D. W. Dye 



and L. Essen, Royal Society of London Proc, v. 143, pp. 285-306, 1934. 



37. The anomaly of nickel steels, Charles Edouard Guillaume, Physical Soc. of London 



Proc, V. 32, p. 374, April, 1928. 



38. La compensation des horloges et des montres; precedes nouveaux fondes sur I'emploi 



des aciers au nickel, Charles Edouard Guillaume. Booklet — Neuchatel et Geneve, 

 Paris, 1920. 



39. Dilatibilit6 du chrome et des alliages nickel-chrome dans un intervalle etendu de 



temperature, P. Ch6venard. Comptes Rendus, v. 174, p. 109, January, 1922. 



40. M6sure de la dilation du coefficient thermoelastique et propri^tes 61ectriques des 



alliages dans un grand intervalle de temperature. R6sultats de I'etude des ferro- 

 nickels purs et additonn^s le chrome. P. Ch^venard. Bull. Soc Franc. Phy. 

 No. 254, pp. 135-138, Dec. 16, 1927. 



41. Tuning forks, H. H. Hagland. U. S. Patent 1,715,324, filed June, 1925, issued May, 



1929. 



42. A mechanical oscillator of constant frequency, August Karolous. U. S. Patent 



1,763,853, filed Nov., 1927, issued June, 1930. 



43. Compensated Tuning Fork, Bert Eisenhour. U. S. Patent 1,880,923, filed Sept., 



1930, issued Oct., 1932. 



