[95] W. A. Heiskanen and F. A. Vening Meinesz, The Earth and its Gravity Field (McGraw: New York, 1958).
[96] F. Kühnen and P. Furtwängler, Bestimmung der Absoluten Grösze der Schwerkraft zu Potsdam mit Reversionspendeln (Berlin: Veröffentlichungen des Königlichen Preussischen Geodätischen Instituts, 1906), new ser., no. 27.
[97] Reported by Dr. F. Kühnen to the fifth session, October 9, 1895, of the Eleventh General Conference, Die Internationale Erdmessung, held in Berlin from September 25 to October 12, 1895. A footnote states that Assistant O. H. Tittmann, who represented the United States, subsequently reported Peirce’s prior discovery of the influence of the flexure of the pendulum itself upon the period (Report of the Superintendent of the U.S. Coast and Geodetic Survey for 1883-84, Washington, 1885, app. 16, pp. 483-485).
[98] Assistants’ Reports, U.S. Coast and Geodetic Survey, 1883-84 (MS, National Archives, Washington).
[99] C. S. Peirce, “Effect of the Flexure of a Pendulum Upon its Period of Oscillation,” Report of the Superintendent of the U.S. Coast and Geodetic Survey for 1883-84 (Washington, 1885), app. no. 16.
[100] F. R. Helmert, Beiträge zur Theorie des Reversionspendels (Potsdam: Veröffentlichungen des Königlichen Preussischen Geodätischen Instituts, 1898).
[101] J. A. Duerksen, Pendulum Gravity Data in the United States (Special Publication No. 244, U.S. Coast and Geodetic Survey; Washington, 1949).
[102] Ibid., p. 2. See also, E. J. Brown, loc. cit. (footnote [85]).
[103] Paul R. Heyl and Guy S. Cook, “The Value of Gravity at Washington,” Journal of Research, National Bureau of Standards (1936), vol. 17, p. 805.
[104] Sir Harold Jeffreys, “The Absolute Value of Gravity,” Monthly Notices of the Royal Astronomical Society, Geophysical Supplement (London, 1949), vol. 5, p. 398.