622 



The Earl of Bosse 



[May 31, 



WEEKLY EVENING MEETING, 



Friday, May 31, 1895. 



Sir Frederick Abel, Bart. K.C.B. D.C.L. LL.D. F.R.S. 



Vice-President, in the Chair. 



The Earl of Rosse, K.P. D.C.L. LL.D. F.R.S. M.B.I. 



The Radiant Heat from the Moon during the 

 Progress of an Eclipse. 



Some twenty-two years ago (May 30, 1873) I delivered in this room a 

 lecture, the title of which was ' On the Radiation of Heat from the 

 Moon, the Law of its Absorption by our Atmosphere, and its Variation 

 in amount with her Phases.' 



Fig. 1. 



I then showed that I had been able, with the aid of a mirror of 

 3 feet aperture, not only to detect with certainty the heat radiated 

 from the lunar surface, but also to estimate with tolerable accuracy 

 the changes of its amount through the greater part of the lunar 

 month, to ascertain roughly the average quality of her rays as regards 

 refractive index, and to compare their amount at the time of Full 

 Moon with those of the Sun. 



