262 The Proposed Pendulum Operations for India. [No. 4, 



Goldingham, at Madras, and afterwards at a small island called Pulo 

 Gaunsah Lout, lying nearly on the equator in East Longitude 98° 50'. 

 The pendulum used was an invariable one, and observations were first 

 taken with it in London, by Captain Kater. From the observations 

 at Madras and London, Mr. Goldingham deduced an ellipticity of -g-^y. 

 Captain Basil Hall, assisted by Captain (then Lieutenant) Henry 

 Foster, made a series of experiments with an invariable pendulum in 

 1820-23, at Galapagos, San Bias (Mexico), Rio Janeiro, and London 

 (Mr. Browne's house). Comparing the results at each of his own 

 stations, with each of Captain Kater's, he deduced ellipticities of -g-g-g-, 

 _i_ and —i- 



3 14) **"■" 3 2" 



In 1822, Sir Thomas Brisbane took with him to Paramatta (near 

 Sydney,) an invariable pendulum that had previously been swung in 

 London, at Mr. Browne's house. He deduced ellipticities of ¥ i ¥ and 

 ■g-i 3 , comparing his observations with those of Kater in London and 

 at Unst. 



In 1817, the French Government fitted out a scientific expedition 

 under the command of Captain Freycinet, who was furnished with 

 three invariable brass pendulums, one of which was similar to Captain 

 Kater's pattern, and the other two had solid cylindrical rods instead 

 of a flat bar. He had also a fourth pendulum, with a wooden rod 

 formed of two plates of deal firmly clamped together. Instead of a 

 clock he used an astronomical counter, (" compteur astronomique") 

 whose beats could be adjusted to synchronism with those of the pen- 

 dulum. The counter had a dial, which showed hours, minutes, and 

 seconds, so that by comparing the time shown by this " compteur" 

 with that of a chronometer, he obtained the number of vibrations 

 made by the pendulum in a certain interval, generally an hour or 40 

 minutes. The pendulums were first swung at Paris, and afterwards 

 at Rio Janeiro, Mauritius, Guam (one of the Ladrone Islands), Mowi 

 (one of the Sandwich Isles), Cape of Good Hope, Port Jackson, 

 Kawak (an island under the line, north of New Guinea) and Malouine 

 or Falkland Isles. Rejecting the determinations at the Mauritius, 

 Guam and Mowi, as they appeared affected to a remarkable degree by 

 local influences, Captain Freycinet deduced an ellipticity of ? }g from 

 all four pendulums. 



On the return of Captain Freycinet, the French government sent 



