250 Mr. herschel on the proper Motion 
my tetefcope, whenever a favourable interval of remarka- 
bly fine weather prefented me with a proper opportunity 
for making ule of them. This review extended to all the 
Bars in flamstead's catalogue, together with every imai-l 
ftar about them, as far as the tenth, eleventh, or twelfth mag- 
nitudes, and occalionallv much farther, to the amount of a 
preat many thouiands of ftars. To Ihew the practicability of 
what I have here advanced, it may be proper to mention, that 
the convenient apparatus of my telefcope is fuch, that 1 have 
many a night, in the courfe o-f eleven or twelve hours of ob- 
iervation, ’ carefully and lingly examined not lels than 400 ce- 
leftial objects, be fide s taking mea lures of angles and pofitions 
of fome of them with proper micrometers, and fometimes 
viewing a particular bar for half an hour together, with all 
the various powers of my telefcope. The particularities 1 at- 
tended to in this la ft review were, 1. The exigence of the ftar 
itfelf, fuch as it is given in the Britilh catalogue. 2. To ob- 
ferve well whether it was double or fingle, well defined or 
hazy. 3. To view and mark down its particular colour, when- 
ever the altitude and fituation of the flar would permit it to be 
done with certainty. 4. To examine all the final! ftars in the 
neighbourhood, as far at leaft as the twelfth magnitude, and 
note tire lame particulars concerning them, except the colours, 
which would have taken up too much time in committing to 
paper, and be of no very material ufe. The refult of thefe 
observations I lhall collect under a few general heads in the 
following articles. 
I. 
Stars that are loll, or have undergone fome capital change, 
fmee flamstead’s time. 
In the Britifh catalogue we find two remarkable ftars of the 
fourth magnitude in the conftellation of Hercules, viz. the. 
