368 
fOPULAH SCIENCE EEVIE^. 
the sun of 29*4 miles per second. Lastly, he considered the 
effect to be ascribed to the sun’s motion, which is directed to- 
wards a point almost exactly opposite Sirius. If Otto Struve’s 
estimate of the solar velocity is correct, then the motion of Sirius 
in the galaxy is reduced to somewhat less than 25 miles per 
second ! 
Interesting as this result is, the fact that the power of the new 
mode of research has been established is yet more so ; for there 
is nothing to prevent the method from being applied in turn to 
all the lucid stars ; nay even, with suitable instrumental power, 
to the telescopic orbs. The results obtained from such re- 
searches cannot fail to be of the utmost value. 
I take myself a special interest in the new method of re- 
search, because I hope to find its results confirmatory and 
elucidatory of certain peculiarities in the stellar motions which 
I have recently been led to notice. On mapping the proper 
motions of about 1500 stars in the manner indicated in fig. 6, I 
have found in many parts of the heavens distinct traces of star- 
drift ; that is, of the systematic motion of groups and sets of 
stars in particular directions. A singular instance of this is found 
among the bright stars of Ursa Major, five of which are moving 
(as shown within the oval, 5, in fig. 6) in the same direction, 
and with the same velocity. Two other stars near ^ are also 
moving in the same manner. One cannot doubt that these 
stars are associated in some way, and so form a system ; 
especially when it is noticed that the stars are moving in a 
direction almost directly opposed to that due to the sun’s 
motion in space. Scarcely less remarkable is the community 
of motion observed within the oval a. And it will be noticed 
that among the remaining stars of the map there is a com- 
munity of motion either inter se, or with the stars included 
within the ovals. 
It will be a matter of extreme interest to determine by Mr. 
Huggins’s method whether the stars which thus seem to form 
drifting systems have a community of motion of recess or of 
approach. Should this be the case, no doubt could possibly 
remain that the stars form sets or groups, and that there is no 
approach to that generally equable distribution described in our 
popular treatises of astronomy. 
