1881] 



President's Address. 



47 



should be compared, by means of invariable pendulums, with gravity 

 at another station belonging to another group. Greenwich has been 

 named as such a station. 



" In connexion with this subject, we would refer to the suggestion, 

 which has been brought before us, made by Mr. Peirce, of the United 

 States Coast Survey, that Major Herschel should swing the same 

 two pendulums that were used in India, first at Kew and then at 

 Washington. 



" As Washington is, or shortly will be, connected differentially with 

 a large chain of stations widely distributed in America and else- 

 where, we think that the value of the Indian series would be 

 decidedly increased by being connected with one of the American 

 stations, such as Washington. We think, however, that its con- 

 nexion through Kew with one of the older series should not on that 

 account be omitted. 



" The observations required for the purpose of these connexions are 

 such as certainly can be made, and have been made, by existing 

 methods ; and the labour of making them, which will be approximately 

 in proportion to the number of stations at which the pendulums will 

 have to be swung, is only a fraction of that already incurred on the 

 Indian stations, and the three which have been included in the same 

 group with them." 



In October last a letter was received from the Treasury asking the 

 opinion of the President and Council respecting arrangements for 

 observing the Transit of Yenus in 1882. Under the advice of a Com- 

 mittee appointed for the purpose, it was recommended that a special 

 Committee of the Royal Society should be appointed to decide upon the 

 observations considered essential, and to advise Her Majesty's Govern- 

 ment as to the best method of carrying them out. In conformity 

 with this advice, and at the request of the Treasury, a Committee was 

 appointed to draw out a scheme of stations, and of the constitution, 

 strength, and equipment of the observing parties, and to frame an 

 estimate of the total cost. The Committee reported recommending the 

 adoption of certain stations in South Africa, the West Indies, Australia, 

 and New Zealand, and the Falkland Islands ; and they at the same time 

 added other particulars, and furnished an estimate of the whole, adopt- 

 ing in the main the recommendations of that Committee ; the Treasury 

 then requested the President and Council to nominate an Executive 

 Committee, by which (accounting to the Treasury) any vote of Parlia- 

 ment for the purpose of these observations might be administered ; and 

 under whose advice the observers and assistants might be selected 

 and appointed. In compliance with this request the following Fellows 

 were nominated as an Executive Committee, viz., the President, 

 Professor J. C. Adams, Sir G. Airy, Mr. Hind, Sir G. Richards, 

 Professor H. J. Smith, and Mr. Stone. That Committee is now con- 



