CATALOGUE OF STARS WITHIN TWO DEGREES 
OF THE NORTH POLE. 
1G 
INTRODUCTORY. 
The first publication of the Vassar College Observatory treats of 
the measurement and reduction of a set of four photographic plates 
covering the region of the sky within one degree of the north pole. 
These photographs were taken at the Helsingfors Observatory, Fin- 
land, and form part of a series of twelve negatives, which together 
include all the stars of less than two degrees polar distance. The four 
plates first treated have their centers at declination go°, the remain- 
ing eight have their centers lying on the circle of 89° declination at 
intervals of 45° right ascension. Because of the high declination this 
procedure results in a peculiar kind of overlapping, the character of 
which can easily be seen by referring to Publication 1, Sec. I, in which 
is given a description of the plates and also an illustrative figure. The 
present paper treats first of the measurement and reduction of the 89° 
plates with a preliminary catalogue of the stars found thereon; sec- 
ond, of the inter-adjustment of the several plates and their combina- 
tion with the former catalogue, a problem which presents considerable 
interest on account of the peculiarity of the overlapping above re- 
ferred to; and third, of the formation of the final catalogue of all the 
stars found on the twelve plates. 
The method of performing the measurement and reduction, which 
form the first part of this paper, is in general the same as that em- 
ployed in Publication 1, Secs. I-VIII. Deviations from it are occa- 
sionally necessary because of the fact that the north pole is no longer 
at the center of each plate but is on the edge. These variations will 
be mentioned in their appropriate places. A detailed description of 
the plates is given in Publication 1, Sec. I. 
The meteorological and other data connected with the exposure 
of the plates were sent from the Helsingfors observatory, and are 
found in the accompanying table. 
