Art. XIII. — Results of Observations zvith the Katers 

 Invariable Penduhtins, made at the Melbourne 

 Observatory. — June to September, i8pj. 



By PiETKO Bauacchi, F.R.A.S. 



[Eead 13th October, 1893.] 



The observations which form the subject of this paper were 

 made with the three Invariable Pendulums of Kater's pattern 

 marked 4, (1821) or 6, and 11, belonging to the Royal Society of 

 London, and fully described in vol. v. of the account of Opera- 

 tions of the Great Trigonometrical Survey of India, and more 

 recently by General Walker in the Philosophical Transactions 

 of the Royal Society, vol. A., 1890, page 539. They were 

 lent to Mr. Ellery for the purpose of being employed in the 

 Gravity Survey of Australia proposed by the Royal Society of 

 Victoria, and to be carried out by a committee specially appointed. 

 These pendulums have been in existence over seventy years, and 

 were swung in many parts of the world, at elevations ranging 

 from sea-level to over 15,000 feet. As stated by General Walker, 

 they were variously employed by Sabine, Bay ley, Airy, and 

 McClear, between the years 1822 and 1854. Captain Basevi took 

 two of them, viz.. No. 4 and No. 6 to India in 1864, where they 

 were employed for eight years in gravity determinations, chiefly 

 at stations along the Central Meridian Arc of the Great Trig. 

 Survey. 



In 1881 aud 1882 Colonel Herschel swung them at Greenwich 

 and Kew, together with Pendulum 11, and afterwards took the 

 three to America, swinging them at Washington and Hoboken. 

 After completing his operations they were given over to Mr. 

 Edwin Smith of the U.S. Coast Survey, by whom they were 

 taken round the world, and swung at Auckland, Sydney, 

 Singapore, Tokio, San Francisco, and again at the starting point, 

 Washington. Lastly, in 1888 and 1889, the Revisionary 

 Operations with the three pendulums at Kew and Greenwich 



