PROCEEDINGS 



OF 



THE ROYAL SOCIETY. 



January 10, 1878. 



Sir JOSEPH HOOKER, K.C.S.I., President, in the Chair. 



The Presents received were laid on the table, and thanks ordered 

 for them. 



The following papers were read : — 



I. " Magnetic Observations taken during the Transit of Venus 

 Expedition to and from Kerguelen Island." By the Rev. S. 

 J. Perry, S.J., F.R.S. Received October 13, 1877. 



In a previous paper, on the elements of terrestrial magnetism 

 observed at Kerguelen, the reason is mentioned why it was not deemed 

 advisable to take magnetic observations at sea during the voyage ; the 

 results, therefore, in this paper are entirely confined to the determina- 

 tions of the Dip, Intensity, and Declination of the earth's magnetic 

 force at the several places at which we landed. On our outward 

 journey we had no opportunity of using our instruments, except at the 

 Cape of Good Hope, but on our return we were much more fortunate, 

 as H.M.S. "Volage" made a stay of at least two days at Point de 

 Galle, at Bombay, Aden, Port Said, and Malta, and we utilised all 

 these opportunities except the first. From Malta, the Rev. W. Sid- 

 greaves and myself returned to England by Sicily, Italy, and France, 

 and, taking our magnetic instruments with us, we were able to observe 

 at Palermo, Naples, Rome, Florence, and Moncalieri. As we had 

 previously made a complete survey of France in 1868 and 1869, we 

 thought it too early to repeat the observations. The instrumental 

 corrections and constants have already been given in the former paper 

 on Kerguelen, it will, therefore, suffice to refer to that communication 

 for any necessary details. 



VOL. XXVII. B 



