﻿B. A. Gould — Determinations of Stellar Positions. 373 



time, but many more, in their measurement and proper compu- 

 tation. 



We photographed no northern stars there except the Pleiades 

 and the Prassepe. Of the Pleiades I brought home sixteen 

 plates, with two impressions of the whole group upon each, 

 made in five different years, from 1872 to 1882, inclusive. 

 Although the center of the cluster never attains a greater alti- 

 tude at Cordoba than 34° 50', some of the plates contain 70 

 stars. All but one of Bessel's stars are there, which belong 

 within the limits of the field, the missing one being of the mag- 

 nitude 9 J, and there are yet other stars of the magnitudes 10, 

 10J-, and 11. Of the Prsesepe, there are five plates, and with a 

 correspondingly increased number of stars. 



About seventy southern clusters have been repeatedly photo- 

 graphed at Cordoba, comprising all those of the southern hem- 

 isphere which seemed important; also somewhat more than a 

 hundred double stars, being a sufficient number to serve as a 

 good test of the method. The total number of photographs 

 now on hand is somewhat less than 1,300, only a few having 

 been preserved in which the images were not circular. 



Especial attention, however, was given, for many years, to 

 taking frequent impressions, at the proper seasons, of four stars 

 selected, on account of their large proper motion, as likely to 

 manifest appreciable annual parallaxes. The refined and elab- 

 orate observations of l)rs. Gill and Elkin, at Cape Town, have 

 been made, computed, and published, while the Cordoba pho- 

 tographs have lain untouched in their boxes. There is but 

 one of my four stars, /9 Hydri, which is not included in 

 their list. Still it will be a matter of much interest to apply 

 the photographic investigation to the same problem, even if for 

 no other purpose than a comparison of the results of the two 

 methods. 



I am convinced that the Cordoba plates contain a large num- 

 ber of stars as faint as the eleventh magnitude of Argelander's 

 scale, and believe that these are much the' earliest photographs 

 of stars fainter than Mr. Kutherfurd's of 1865 and 1866. There 

 are several plates, covering about a degree square, which can- 

 not contain less than 550 stars, and I believe that some of them 

 contain a greater number. Such are those of the cluster Lac. 

 4,375 and that near x Carinas. 



The region in the vicinity of rj Carinas, and that magnifi- 

 cent tract in Sagittarius which is too densely sown with stars 

 to be considered merely a portion of the Milky Way, and yet 

 too large and undefined to be regarded simply as a cluster, 

 were both of them taken several times, during the years 1875 

 to 1882, in series of overlapping photographs, each containing 

 about a square degree, and recorded upon a glass surface of 9 



