170 
EASTMAN. 
in stellar astronomy, and in that direction, in the hands of 
such a master, it served a useful purpose. 
The most important obstacle, in all the discussions of solar 
and stellar motions, is our almost complete ignorance of the 
distribution and the distances of the stars. While it is true 
that the parallaxes, and consequently the distances of a 
very few stars, have been measured with considerable appar¬ 
ent accuracy, the probable error of many of the most trust¬ 
worthy results, if expressed in miles, would be greater than 
any known distance in the solar system. 
But even if we knew the distance from the solar system of 
any star of a given magnitude, or of a number of stars of dif¬ 
ferent magnitudes, with as much precision as we know the 
distance of the earth from the sun, we should only be in pos¬ 
session of a few isolated facts, and would be unable, from 
such data, and with the knowledge we have thus far attained, 
to infer the distance of any other star in the universe. 
Our knowledge of stellar distances must be obtained by 
the slow and laborious process of measuring the parallax of 
each object, trusting that, with the gradually accumulating 
facts, new light may be thrown upon the problem, and a 
second Newton may appear, who will solve the riddle, and 
point out to future astronomers the laws that obtain among 
the stellar worlds. 
It is well, perhaps, to consider at this point, one important 
fact. If, at this moment, we knew the distance from the solar 
system of every star visible to the naked eye, with an ac¬ 
curacy equal to the best work ever done in that direction, 
we should still he unable to solve the problem of the direc¬ 
tion and the velocity of the motion of the solar system, with 
a degree of precision commensurate with the importance of 
the question. 
But we are not yet in possession of the necessary accurate 
knowledge of the proper motions of the stars. 
While many of the earlier observations of right ascen¬ 
sions are fairly trustworthy, it is only about ninety years 
since Pond’s observations, with astronomical instruments of 
