(* 196° ) 
N°. XIII. 
Accurate determination of the right afcenfion and declina- 
tion of & Bootes, andthe Pole Star: m a Letter from 
Mr. ANDREW Exuicotr to Mr. R. PATTERSON. 
Dear Sir, Odober 17th, 1788. 
Read Nov. fF HEREWITH fend you the right afcenfions 
ie oe | and dechnations of #4 Bootes, and the~ Pole 
Star. ‘The Declination of ~ Bootes was determined by 
comparing its zenith diftance, with the zenith diftances of 
« Lyre, Capella, « Cygni, y Andromedez, 4 Medufz, and 
’ Cygni, whofe declinations have been accurately deter- 
mined by the European aftronomers. The zenith diftan- 
ces, were taken by the fector which was ufed on the North- 
ern boundary of this ftate, and was made by our own 
countryman Mr. Rittenhoufe, and graduated by a method 
of his own; to fay more in its favour, would be fuper- 
fluous. The right afcenfion was determined by comparing 
its paflage over the meridian, with the moft convenient of 
thofe contained in the roth table, annexed: to the firft 
Volume, of the Rev. Do&. Mafkelyne’s aftronomical ob« 
fervations. ‘This flar will be found very ufeful, in de- 
termining latitudes within the Northern, and Southern 
limits of the United States. 
The right afcenfion and declination of the Pole ftar, I 
have deduced from the obfervations of the Rev. Do€or 
Mafkelyne. This ftar is of fuch confequence in tracing 
a meridian, thatitis a wonder fo little attention has been 
paid to it by the European aftronomers : it is however lia- 
ble to one inconvenience, on account of the change in its. 
annual variation in right afcenfion; but this may be near- 
ly correted for many years, by ufing an arithmetical pro- 
greflion, an example of which will be found at the end of 
the tables of aberration and nutation. In 
