158 
EASTMAN. 
and velocity of the solar motion; using as data the proper 
motions determined by Argelander for his well known list 
of 250 stars, and also the proper motions from 95 other tele¬ 
scopic stars which had been observed by Argelander. He 
divided the 345 stars into four groups, depending upon the 
amount of proper motion, as follows: 
The first group contained 19 stars with proper motions 
greater than l".000. 
The second group contained 24 stars with proper motions 
between 0".70'1 and 1".000. 
The third group contained 65 stars with proper motions 
between 0A401 and 0".700. 
The fourth group contained 237 stars with proper motions 
between O''.050 and 0".400. 
He found a position of the Solar apex from each group 
separately, but finally adopted the following values derived 
from combining the data from all the stars : H. A. — 285°.2; 
Dec. = + 48°.5. 
He also found the annual, angular value of the solar mo¬ 
tion to be 0A3367. 
In March, 1887, Ludwig Struve, 27 a member of the third 
generation of Russian astronomers who have borne the name 
of Struve to the great credit of the empire, presented to the 
St. Petersburg Academy of Sciences an important paper en¬ 
titled “ Bestimmung der Constante der Praecession und der 
Eigenen Bewegung des Sonnensystems.” He adopted in his 
computations the method of rectangular coordinates as used 
by Airy, and also assumed for the stars the same relation be¬ 
tween magnitude and distance. The author used the proper 
motions of 2509 stars whose earliest positions depend upon 
Dr. Auwer’s late re-reduction of Bradley’s observations, 
while the modern places were taken from the Pulkowa Cata¬ 
logues for the epochs 1845, 1855 and 1865. From this dis¬ 
cussion, the coordinates of the solar apex, for the epoch 1805, 
27 Struve, Ludwig. Memoires de PAcademie Imp. de St. Petersbourg. 
vii® Serie, Tome xxxv, No. 3. 
