380 PROCEEDINGS OF THE AMERICAN ACADEMY 



XX. 



OBSERVATIONS OF VARIABLE STARS IN 1886. 

 By Edward C. PickepxIng. 



Communicated March 9, 1887. 



The present publication is the fourth in a series of annual state- 

 ments relating to variable stars, which was begun in 1884. In the 

 fifth statement, to be published in 1888, it is proposed to review the 

 entire period since the discovery of each variable star, giving the num- 

 ber of observations made by each observer during each year, so far as 

 this information can be obtained. All persons who have any facts of 

 this kind at command are urgently requested to communicate them to 

 the Observatory of Harvard College, so that the proposed publication 

 may be as complete as possible. 



Some difficulty has been experienced in preparing the present re- 

 port, from the circumstance that variable stars are occasionally desig- 

 nated only by letters and constellations, without their numbers in any 

 published catalogue or their places for a given date. The recommen- 

 dation made in previous reports is accordingly here renewed, that the 

 place of each star should always be given when there is no other 

 means of identification than the name. The number in a designated 

 catalogue, such as that printed with these reports, will of course be a 

 sufficient substitute for the place. 



In view of the extended publication proposed for next year, the 

 present report may be made comparatively brief. The names of the 

 observers, their methods of observation, and the abbreviations by 

 which they are designated in Tables I. and II. are mainly the same 

 as in the report for last year; Messrs. Backhouse, Duner, Eadie, 

 Espin, Gore, Hagen, Knott, Parkhurst, Safarik. and Zaiser, being 

 designated as before by B., D., Ee., En., G., Hn., K., P., Sk., and Zr., 

 while M. denotes the work of the meridian photometer. An eyepiece 

 magnifying 90 times has often been employed in Mr. Parkhurst's 

 observations, in addition to the powers of 56 and 150 mentioned last 



