84 
MR. GALLOWAY ON THE PROPER 
A third deduction from Mayer’s table was made by Klugel, in the Berlin Ephe- 
meris for 1789. After giving formulee for determining from the observed variations 
in the positions of the stars the direction of the sun’s motion in space, he applies 
them to the proper motions given in the table, and finds the pole towards which the 
sun’s motion is directed to be at the point of which the right ascension is 260° and 
north declination 27°. This differs from Sir W. Herschel’s determination only by 
3° of right ascension, and 2° of declination. 
Although the general agreement of these three results was calculated to draw the 
attention of astronomers to the subject, and served, at least, to give a certain plausi- 
bility to the hypothesis, no further addition was made to the data of the problem till 
the publication, in 1790, of Dr. Maskelyne’s table of the proper motions of thirty-six 
stars. This table, which furnished much more certain data than had previously 
existed, gave occasion to a second elaborate memoir by Sir William Herschel, 
which appeared in the Philosophical Transactions for 1805. 
The mode of proceeding employed by Sir W. Herschel in this memoir merits atten- 
tion. Having computed from the observed variations of right ascension and declination 
the apparent direction of the proper motion of each of the stars, he traced on a celestial 
globe the great circles in which they were contained. On the supposition that the 
variations in question were parallactic motions caused by the translation of the sun, it 
was evident that all the great circles containing them would intersect each other in 
the same two opposite points of the sphere. Now of the intersections thus formed 
by taking the stars in pairs, he found ten made by six stars of the first magnitude 
to be contained within a very limited portion of the heavens about the constellation 
Hercules, while (he remarks) “ upon all the remaining surface of the globe there 
was not the least appearance of any other than a promiscuous situation of intersec- 
tions, and of these only one was made by arches of principal stars.” The six stars 
which gave the contiguous intersections were Sirius, Arcturus, Capella, Lyra, Alde- 
baran and Procyon. But six stars combined by pairs give fifteen intersections ; of 
these, therefore, five were rejected, that is to say a third of the whole, as not agreeing 
with the hypothesis. He then computes, by a trigonometrical calculation, the exact 
situations of the points of intersection of the ten arches, and (taking the points from 
which the stars appeared to recede) found them to be all included between 235° and 
290° of right ascension, and between 17° and 58° of north declination. He then takes 
into account the motions of three other large stars, of the second order, and, on combi- 
ning them with those of the former six, found out of the whole number of new inter- 
sections fifteen which agreed with the former in “ pointing out the same part of the 
heavens as a parallactic centre.” The positions of these fifteen new points were not 
calculated, but determined graphically ; he conceived, however, they might be 
depended on as true to one degree of the sphere. 
to come within the sphere of the sun’s attraction, ought it not (he asks) to happen that more comets will ap- 
pear in the quarter of the heavens towards which the sun is advancing than the opposite quarter ? 
