382 PROCEEDINGS OF THE AMERICAN ACADEMY 



Durchmusterung, when they occur in that catalogue, should be en- 

 tered in the lists thus sent. 



Sn. These observations were made by Mr. T. S. H. Shearmen, of 

 Brantford, Canada. The instruments employed were an opera-glass 

 and a two-inch refractor. Each variable was compared with stars 

 differing little from it in brightness. Many suspected variables have 

 been photographed. 



Table I. indicates the progress of observation for stars included in 

 Table I. of previous reports. Other stars, whether known or sus- 

 pected to be variable, are included in Table II. All the columns of 

 Table I. except the last are repeated from the statement of the pre- 

 vious year. The first column of the left-hand pages gives a provis- 

 ional number for designating the star. This number is taken from 

 Schiinfeld's Catalogue when the star occurs there ; in other cases, a 

 letter is added to the number. The second column contains numbers 

 from the Photometric Catalogue called Harvard Photometry, and 

 published in Volume XIV. of the Annals of the Harvard College 

 Observatory. The following columns contain the usual designation 

 of the star, its right ascension and declination for 1875, magnitude at 

 maximum and minimum, and period in days. 



The first column of the right-hand page repeats the number to be 

 used for the provisional designation of the star. The second gives 

 the class to which the star belongs, upon the system of classification 

 employed in the Proceedings of the American Academy of Arts and 

 Sciences, XVI. 257. Upon this system, Class I. includes temporary 

 stars ; Class II., stars undergoing large variations in periods of sev- 

 eral months ; Class III., irregularly variable stars, undergoing but 

 slight changes in brightness ; Class IV., variable stars of short period, 

 like (i LyroE or S Cephei ; Class V., Algol stars, or those which at 

 regular intervals undergo sudden diminutions of light, lasting for a 

 few hours only. The third column gives the name of the discoverer, 

 and the fourth column the date. 



The last column contains the number of nights on which each star 

 was observed by the astronomer whose designation is attached to the 

 number. The abbreviations employed have been explained above. 



Table I. is followed by a series of remarks containing observed 

 dates of maximum and minimum, and other information derived from 

 the observers with regard to particular stars. 



Table II. indicates the progress of observation of stars suspected or 

 known to be variable, but not included in Table I. for reasons ex- 

 plained in previous reports. The provisional numbers given in (he 



