[ 306 ] 

 XXXIX. Proceedings of Learned Societies. 



ROYAL SOCIETY. 



[Continued from p. 231.] 



January 16, 1873. — T. Archer Hirst. Ph.D., Vice-President, in 

 the Chair. 



rpiIE following communication was read : — 

 -*- "Additional jSTote to the Paper ' On a supposed Alteration in 

 the Amount of Astronomical Aberration of Light produced by the 

 Passage of the Light through a considerable thickness of Refracting 

 Medium/ " By the President. 



Some months since I communicated to the Royal Society* the 

 result of observations on y Draconis made with the water-telescope 

 of the Royal Observatory (constructed expressly for testing the 

 equality of the coefficient of sidereal aberration, whether the tube 

 of a telescope be filled with air, as usual, or with water) in the 

 spring and autumn of 1871. Similar observations have been 

 made in the spring and autumn of 1872, and I now place before 

 the Society the collected results. It will be remembered, from 

 the explanation in the former paper, that the uniformity of re- 

 sults for the latitude of station necessarily proves the correctness 

 of the coefficient of aberration employed in the Kautical Almanac. 



Apparent Latitude of Station. 



o 



1871. Spring 51 28 34-4 



Autumn 51 28 33-6 



1872. Spring 51 28 33*6 



Autumn 51 28 33-8 



I now propose, when the risk of frost shall have passed 

 away, to reverify the scale of the micrometer, and then to dismount 

 the instrument- 

 Jan. 23. — T. Archer Hirst, Ph.D.. Vice-President, in the Chair. * 



The following communication was read : — 



"jSTote on the V icle-sht Method of viewing the Solar Promi- 

 nences." By William Huggins, D.C.L., L.L.D., F.K.S. 



"When editing the English translation of Schellen's ' Spectrum 

 Analysis/ I discovered that the short account of the method of 

 viewing the forms of the solar prominences by means of a wide 

 slit, which I had the honour of presenting to the Royal Society 

 on February 18, 1869 1, does not agree exactly in one respect 

 with the account of the observation of February 13 as it was 

 entered at the time in my observatory book. The short note was 



* Phil. Mag. vol. xliii. p. 310. 



t Phil. Mag. S. 4, vol. xxxviii p. 68. 



