352 Mr. Wollaston’s Defcriptioti , &c. 
' 
tion, and its line in another column for right afcenfion, and 
under each the con if ant iin. a-\ -q, and the arithmetical comph 
of iin. a ; thefe being added together will make two lums, 
for the comparative obfervations of every ftar which may pais 
vour field ; and, unlefs your field be very large, and the decli- 
nation of the ifars very great, if to the column for declination 
you add the coiine of decimation of the center of your held, it 
will adapt itfelf to all the produdls. 
FRANCIS WOLLASTON. 
Char ter-houfe -Square, 
March 15, 1785. 
POSTSCRIPT. 
SINCE the delivery of this Paper, it has occurred to me, 
that it may fometimes be convenient to know the angle of 
deviation from the true equatorial poiition in the new fyftem of 
wires. This is to be deduced nearly in the fame manner as in 
the rhombus ; for = tang. q. By this angle any obferved 
differences in right afcenfion may be corrected : for the dif- 
ference in declination between any two ffars (or their dif- 
ference from the angle) multiplied by fin. q, will give the cor- 
rection required. i 
