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104. Split second time runs today's world, F. Barrows and Catherine Bell Palmer, The 



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105. Frequency and Time Control Aided by Telephone Company, H. C. Forbes and F. 



Zaugbaum, Electrical World, pp. 117-118, January 20, 1934. 



106. Generation of reference frequencies, L. A. Meacham, Bell Laboratories Record, v. 



17, pp. 138-140, January, 1939. 



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112. The national primary standard of radio frequency, E. L. Hall, V. E. Heaton and 



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113. Crystal clock for accurate time standard, Vincent E. Heaton, Instruments, v. 20, 



No. 7, pp. 618-619 July, 1947. 



114. W.W.V. standard frequency broadcasts, W. D. George, F.M. and Television, v. 7, 



pp. 25-27, June, 1947. 



115. Time service of the U. S. Naval Observatory, J. Frederick Hellweg, Trans. A. L E. E., 



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116. Quartz crystal clocks — How Greenwich mean time is determined, Humphry M. 



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117. The Measurement of Time, H. Spencer Jones. Reports on Progress in Physics, 



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118. Proceedings of Observatories — Royal Observatory, Greenwich. H. Spencer Jones, 



Monthly Notices of R.A.S., v. 103, No. 2, pp. 77, 78, 1943. 



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L. S. T. Symms, Monthly Notices of R. S. A., v. 103, No. 4, pp. 196-209, 1943. 



120. (a) High precision timekeeping — Quartz clock now supersedes free pendulum. F. 



Hope-Jones, Horological Journal, October, 1943. 



120. (b) The precision timekeeping revolution — More about the Quartz Clock. F. Hope- 



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121. A quartz clock, C. F. Booth, P.O.E.E. Journal, v. 39, Part II, pp. 33-37, July, 1946. 



122. A standard of frequency and its applications, C. F. Booth and F. J. M. Laver, 



The Journal of the L E. E., v. 93, part III, pp. 223-236, July, 1946. 



123. Theory and practice of pendulum observations at sea, F. A. Vening Meinesz. 



Netherlands Geodetic Commission, 1929. 



1 24. Gravitational force measuring apparatus, W. A. Marrison. U. S. Patent No. 2,319,940, 



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125. The Dye quartz ring as a standard of frequency and time, L. Essen, Proc. Royal 



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126. A new form of frequency and time standard, L. Essen, Proc. Phys. Soc. of London, 



V. 50, pp. 413-426, 1938. 



127. Crystal oscillators for radio transmitters: An account of experimental work carried 



out by the Post Office. C. F. Booth and E. J. C. Dixon. Jl. L E. E., v. 77, pp. 

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128. Thermostat design for frequency standards, W. A. Marrison, Proc. /. R. E., 



V. 16, No. 7, pp. 976-980, July, 1928. 



129. Superconductivity of lead at 3-cm. wavelength. F. Bitter, J. B. Garrison, J. Hal- 



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130. Enc. Brit. 14th Ed. See "Joseph von Fraunhofer". 



