OF ARTS AND SCIENCES. 321 



about 50. Argelander's method of comparisou is used. A copy of the 

 observations has been furnished to the Harvard College Observatory. 

 Mr. Eadie acts in co-operation with Mr, Parkhurst in a manner which 

 is explained in the remarks upon Mr. Parkhurst's observations. This 

 system of co-operation appears to be highly efficient and economical. 

 It deserves extension and general introduction among observers not 

 too far separated for ready communication with each other. 



En. These observations were made by the Rev. T. E. Espin, of 

 Walsingham, Darlington, England. The instruments employed were 

 a binocular glass and reflecting telescopes of 9 and 17|- inches in 

 aperture, the last by Calver. 



G. These observations were made by Mr. J. E. Gore, of Ballyso- 

 dare, Ireland, by Argelander's method. The instrument was a binocu- 

 lar field-glass having object-glasses of 2 inches in aperture, and a 

 magnifying power of about six diameters. 



Hg. These observations were made at Dorpat, by Dr. E. Hartwig. 



Hn. These observations were made by the Rev. J. Hagen, S. J., at 

 the College of the Sacred Heart, Prairie du Chien, Wisconsin. The 

 instrument is a telescope by Merz ; its aperture is 3 inches. The ob- 

 servations were made by the division into tenths of the interval be- 

 tween two comparison stars. A copy of the observations has been 

 furnished to the Harvard College Observatory. Mr. Zaiser has taken 

 part in the work as an assistant. 



K. These observations were made by Mr. George Knott, at 

 Knowles Lodge, Cuckiield, Hayward's Heath, England. The tele- 

 scope employed was made by Alvan Clark and Sons ; its aperture is 

 7^ inches, and that of the finder 2 inches. The variable is compared 

 with stars differing little from it in brightness ; the magnitudes of the 

 comparison stars, and sometimes the magnitude of the variable, are 

 determined by the method of limiting apertures. 



M. These observations, which relate exclusively to suspected vari- 

 ables, were made with the meridian photometer of the Harvard Col- 

 lege Observatory. The observers using this instrument are E. C. 

 Pickering and 0. C. Wendell. The magnitudes of the stars observed 

 with it are referred to a series of one hundred circumpolar stars, the 

 brightness of which was determined by observations described in Vol- 

 ume XIV. of the Annals of the Observatory. 



P. These observations were made by Mr. II. M. Parkhurst, at 

 Brooklyn, N. Y. The instrument is a telescope made by Fitz ; its 

 aperture is 9 inches, and the magnifying powers employed are 56 and 

 150. Many of the observations are made by Argelander's method, 



VOL. XXI. (N. S. XIII.) 21 



