TABLES 87-88. 

 LENGTH OF THE SECONDS PENDULUM. 



TABLE 87. -Length of Seconds Pendulum at Sea Level lor Different Latitudes.* 



ID/ 



* Calculated from force of gravity table by the formula lg/it*. For each 100 feet of elevation subtract 0.000596 

 centimetres, or 0.000235 inches, or .0000196 feet. 



TABLE 88. Length of the Seconds Pendulum.* 



1 Laplace r "Traite de Mecanique Celeste," T. 2, livre 3, chap. 5, sect. 42. 



2 Mathieu: " Sur les experiences du pendule;" in " Connaissance des Temps 1816." 

 Additions, pp. 314-341, p. 332. 



3 Biot et Arago : " Recueil d'Observations geodesiques, etc." Paris, 1821, p. 575. 



4 Sabine : " An Account of Experiments to determine the Figure of the Earth, etc., by 

 Sir Edward Sabine." London, 1825, p. 3^2. 



5 Saigey : _" Comparaison des Observations du pendule a diverses latitudes; faites par 



Mathe- 



MM. Biot, Kater, Sabine, de Freycinet, et Duperry ; " in " Bulletin des Sciences M; 

 matiques, etc.," T. i, pp. 31-43, and 171-184. Pans, 1827. 



6 Pontecoulant : " Theorie analytique du Systeme du monde," Paris, 1829, T. 2, p. 

 Airy : " Figure of the Earth ; " in " Encyc. Met." 2d Div. vol. 3, p. 230. 



466. 



PP. 



p. 316. 



10 Fischer : " Die Gestalt der Erde und die Pendelmessungen ; " in " Ast. Nach." 1876, 

 col. 87. 



11 Helmert: "Die mathematischen und physikalischen Theorieen der hoheren Geo- 

 dasie, von Dr. F. R. Helmert," II. Theil. Leipzig, 1884, p. 241. 



12 Harkness. 



* The data here given with regard to the different determinations which have been made of the length of the 

 seconds pendulum are quoted from Harkness (Solar Parallax and its Related Constants, Washington, 1891). 

 t Calculated from a logarithmic expression given by Unferdinger. 



SMITHSONIAN TABLES. 



