Note 89 — DEVELOPMENT OF GRAVITY PENDULUMS IN THE 19th CENTURY

P. Furtwängler, “Über die Schwingungen zweier Pendel mit annähernd gleicher Schwingungsdauer auf gemeinsamer Unterlage,” Sitzungsberichte der Königlicher Preussischen Akademie der Wissenschaften zu Berlin (Berlin, 1902) pp. 245-253. Peirce investigated the plan of swinging two pendulums on the same stand (Report of the Superintendent of the U.S. Coast and Geodetic Survey for 1880-81, Washington, 1883, p. 26; also in Charles Sanders Peirce, Collected Papers, 6.273). At a conference on gravity held in Washington during May 1882, Peirce again advanced the method of eliminating flexure by hanging two pendulums on one support and oscillating them in antiphase (“Report of a conference on gravity determinations held in Washington, D.C., in May, 1882,” Report of the Superintendent of the U.S. Coast and Geodetic Survey for 1881-82, Washington, 1883, app. no. 22, pp. 503-516).