Note 1 — DEVELOPMENT OF GRAVITY PENDULUMS IN THE 19th CENTURY

The basic historical documents have been collected, with a bibliography of works and memoirs published from 1629 to the end of 1885, in Collection de mémoires relatifs a la physique, publiés par la Société française de Physique [hereinafter referred to as Collection de mémoires]: vol. 4, Mémoires sur le pendule, précédés d’une bibliographie (Paris: Gauthier-Villars, 1889); and vol. 5, Mémoires sur le pendule, part 2 (Paris: Gauthier-Villars, 1891). Important secondary sources are: C. Wolf, “Introduction historique,” pp. 1-42 in vol. 4, above; and George Biddell Airy, “Figure of the Earth,” pp. 165-240 in vol. 5 of Encyclopaedia metropolitana (London, 1845).