110 RECORD OF SCIENCE FOR 1886. 



lars of nearly two liuiulreil stars for 1885. The work has been done by 

 co-operation. All who are willing to assist (a tiekl-glass is sufticient 

 instriunental equipment), are requested, to send accounts of their work 

 to the Harvard Observatory as soon as possible after the close of each 

 year. Professor Pickering undertakes to make photometric observa- 

 tions of all comparison stars needed. . 



Mr. Mspin, the special observer of the Liverpool Astronomical Society, 

 has commenced the issue of a circular calling- attention to various vari- 

 able stars or stars suspected of variability. 



Several interesting cases of variability have been discovered by 

 Messrs. Chandler and Sawyer, of Cambridge. The most interesting case 

 is a new variable of the Algol type discovered by Mr. Chandler in the 

 constellation Cygnus {II. A. 20'' 48"' ; Decl. + 34° 14'). The range is from 

 7.1 magnitude to 7.8 magnitude, the whole variation taking place in 

 about SIX hours. The only doubt is in regard to the interval during 

 which the star remains at its normal magnitude. Mr. Chandler sus- 

 pects that the whole duration between two successive periods of change 

 will be found to be about one day, twelve hours. 



Gore's nciv variable near x^ Orionis {Nora Orionis). — A mass of obser- 

 vations by skillful observers has accumulated, and will repay a thor- 

 ough study. 



It seems to be clearly established that this interesting star is a sim- 

 l)le variable, and not one of the class to which the title " temporary " 

 can properly be applied. M. Duner, who observed the star at inter- 

 vals from December, 1885, to April, 1886, found (Astron. T^achr., No. 

 2755), on renewing his observations at the end of October and the 

 beginning of November, 1880, that it had unmistakably increased 

 in brightness in the interval, and was continuing to do so. Herr 

 Ft. Schwab and Mr. Espin confirm this conclusion, the former having 

 observed the star early in last July, and having found it then fainter 

 than the twelfth magnitude. Its period would appear to be not far 

 from one year ; Herr Schwab gives it as one or two weeks longer than 

 one year, and as ranging in brightness from the sixth magnitude to 12i, 

 whilst M. Dun6r assigns a period of 359.5 days. (Nature.) 



According to Dr. Vogel and others who have examined its spectrum, 

 it belongs to Type 111 a, resembling the spectrum of cy Orionis. 



The new star in the (jrcat nebula of Andromeda. — Professor Seeliger 

 has published (Astron. Nachr., No. 2710) an interesting paper contain- 

 ing an attempt to represent the observed variations of the light of the 

 Novam Androme<la by a formula expressing the rate of cooling of a 

 hot sphere. Supposing that such a body has its temperature suddenly 

 increased to an enormous extent by some shock, its brightness will of 

 course be increased also. And assuming that the latter is proportional 

 to the wth power of the temperature, and using Pogson's scale for trans- 

 forming brightness into stellar magnitude. Professor Seeliger (making 



