26 catalogue; op stars within 
The right ascensions and polar distances of the stars were deter- 
mined from the measured coordinates according to the method given 
in PubHcation i, Sec. IV, with one modification. Certain terms in 
the right ascension equation which are neghgible for the 90° plates 
where the pole is very near the center, must be included for the 89° 
plates, where the pole is a degree from the center. Furthermore, 
since there is an obvious error in the last line on p. 27, the form 
given in the first equation for « on p. 28 is incorrect. The correct 
form and the one which has been used in the present investigation 
is given below, and with it is repeated for convenience the equation for 
polar distance. 
:T = pio — ^Pp' cos'B" co' sin' i" — IP {X' -{-¥') co' sin' i" (la) 
-^ipWsin'i". 
Since the small terms in « are negligible in any case for the 90° 
plates, the equations which were used in the first paper, i. e., equations 
(i), are correct as they stand. 
The plate constants were determined according to the method of 
Sees. V to VII. The right ascensions and polar distances of the stand- 
ard stars were taken from Elkin's Heliometer Triangulation of Stars 
in the Vicinity of the North Pole.* All of the stars in this work, 
twenty-four in number, were used with the exception of Polaris, the 
photographic images of which were not suitable for measurement. 
The companion of Polaris was obscured by the primary on every plate 
but one, namely, Sept. 21, no. 15. The following Table III, gives the 
polar coordinates of the standard stars together with their numbers 
in the final catalogue by means of which their rectangular coordinates 
may be taken from Table 11. 
* Transactions of Yale Observatory, Vol. I, part III. 
