Mr . pigott*s Account of double Stars, &e. 85 
declinations were deduced from the difference of altitudes : be- 
tween the double .ftars and the known ftars, to which they were 
compared, as (hewn by the graduated femi-circle of the traniit 
inftrument, which, being divided to two minutes only, cannot 
be fuppofed to give any great precifion : however, I believe, 
their declinations, hence deduced, to be corredt to one minute, 
or one minute and a half 
In obferving the double ftar compared to Z Pegafi, I found it 
impoflible to illuminate the wires of the tranfit inftrument, 
without nearly obliterating the ftar.. This difficulty led me to 
a method, which, as it completely fucceeded^ may, under fimi- 
lar circumftances, jpoffibly. be of ufe to others* A perfbn illu- 
minating the \vires very, faintly, fo that I could juft perceive the 
double ftar, at a fignal totally withdrew the light : this fignal 
I made when the double ftar was nearly as far diftant from the 
firft wire as the five wires are diftant from each other, which, 
in this cafe, was 13" by the clock. I then counted the fecond s* 
and did not N fail to fee the ftar diiappear a fecond or two within 
the time expedted. On its difappeanng, I made a fignal to 
write down; and then beginning to count again, did the 
fame at each wire. I have fince tried this method with other 
ftars, and think they may he thus obferved, even with greater 
precifion than when the wires are illuminated. Hence the 
troublefome bufinefs, well known to aftronomers, of illumi- 
iiating faint objedt s, may be removed. * \ . 
The preceding ftar of each double ftar was obferved on the 
firft, third hid fifth wires, and the following one oii the fecond 
•and fourth wires:; and thus their difference in R. A. in time, 
converted into p&rts of a great circle, obtained. Suppofing the 
apparent R. A. and App. declinations of a Delpbini, /3 Aquarii, 
and £ Pegafi, as here a ftumed, the places of thefe double ftars 
were found to be as follows. 
I beg 
