Proceedings of the Royal Society. 297 



this conclusion be just, the author remarks, that it opens a new 

 field of inquiry, which may help to explain several phenomena in 

 mineralogy and geology. 



At the same meeting a paper was also read, entitled Observa- 

 tions of the Apparent Distance and Positions of 460 double and 

 triple Stars, made in the years 1823, 1824, and 1825, together with 

 a re- examination of 36 Stars of the same description, the distances 

 and positions of which were communicated in a former Memoir, by 

 James South, F.R.S. 



The author prefaces these observations with a brief account of 

 the instruments with which, and the circumstances under which, 

 they were made. The former being the same with which the ob- 

 servations previously communicated to this society were made, 

 and being fully described in the former paper alluded to in the 

 title of this, require no further particular description ; he con- 

 tents himself therefore with noticing that by a different adapta- 

 tion of their parts, higher magnifying powers than those formerly 

 employed were obtained, and a series of powers from 92 to 7S7 

 used in a part of the observations. 



A large portion of these observations were made at Passy, near 

 Paris ; and the author takes occasion to make honourable mention 

 of the facilities afforded him on the part of the French government, 

 for the ingress and regress of his instruments into and out of 

 France, and of the attention and assistance uniformly afforded 

 him while resident there by many distinguished individuals. 



Of the stars whose measures are here presented, he states that 

 about 160 are hitherto undescribed, and probably new. The places 

 of these are given merely with sufficient exactness to enable any 

 one to find them in future. The remainder are in great measure 

 stars comprised in M. Struve'3 catalogue of 796 double and triple 

 stars, and among these about 160 belong to those examined for 

 the first time by Sir Wm. Herschel. 



The observations themselves are stated in a manner somewhat 

 different from that adhered to in the former communication al- 

 ready alluded to. Instead of giving all the individual microme- 



