Progress of Astronomy during the Year 1879. 465 
carefully noted. Three years were spent in this survey, and 
since then Mr. Thorne has twice reviewed the entire work, so 
that Mr. Gould considers it improbable that any star as bright 
as 7:0 magnitude has escaped detection, whilst the magnitudes 
are believed to be essentially correct to the tenth of a magnitude. 
The total number of stars is 10,649, and the total number of 
estimates of magnitude 44,510. All the stars have been ob- 
served at least four times each for accurate position with the 
transit-circle. The charts are 13 in number, besides an index 
map giving the whole limit, and containing stars down to the 
fifth magnitude. The letterpress contains first the catalogue 
of approximate positions, magnitudes, &., and next a discussion 
of the distribution of the stars, according to their brightness. 
Dr. Gould finds that by collecting all stars to the ninth magni- 
tude, and distributing them according to classes, there is always 
an excess in the number of bright stars observed over those 
which result from calculation on the supposition that the stars 
increase regularly in number as they diminish in brightness, 
but that the accordance is much closer for the faint stars. It 
is not assumed that the stars are all of the same size, and that 
they vary in brightness according to their distance from the 
observer—in fact we know that if our sun were removed to 
the distance of an average first magnitude star it would shine 
as one of the third or fourth magnitude; but it cannot be 
doubted that the average distance of all the fifth magnitude 
stars is nearer to us than the average of all the sixth magnitude. 
Reasoning from this excess of the bright stars, and the exist- 
ence of a belt of bright stars girdling the heavens, inclined to 
the galaxy at an angle of about 20° at its greatest deviation, and 
intersecting it in two nodes, twelve hours apart, he concludes 
that we are situated in a cluster, numbering probably 400 stars, 
and ranging in magnitude from first to seventh. This belt 
being very marked in the south, and less so in the north, he 
considers that our position in it is on that side, in the direction 
of Hercules, the point in the heavens towards which our solar 
system is moving. 
A series of measures of the Milky Way as given on the 
Cordoba charts and Heis’s atlas was made and discussed. The 
circle resulting from these measures is very nearly a great one, 
Scien. Proc., R.D.S. VOL. 11., PT. vi. aT 
