254 An EASY METHOD of FINDING THE 
neareft whole degree, then move the fcrew till the objec 
appears in the direction of the fights, and the nonius on 
the movable fight will point out the odd minutes. 
Explanation and Ufe of the TaBLe. 
The left hand double column of the table contains the 
time before the ftar’s paflage over the meridian above the 
pole, for every twenty minutes of its whole diurnal circuit. 
The firft column, under each particular latitude, fhews 
the azimuth of the ftar at thefe times, refpectively, in de- 
grees, minutes and tenths of a minute. The fecond co- 
lumn fhews the difference of azimuth in every twenty 
minutes of intermediate time, in minutes and tenths. 
To find the true azimuth of the ftar in any latitude, at 
any given time. 
From the ftar’s right afcenfion, viz. o" 49”, increafed by 
24° if neceflary, fubtra&t the right afcenfion of the fun 
computed to the time of the ftar’s paflage over the meri- 
dian, above the pole, nearly, the remainder will be the 
time of faid paflage, reckoned from noon. From which, 
inereafed by 24" if neceflary, fubtract the time of the ob- 
fervation, reckoned alfo from noon, the remainder will 
fhew the time before the ftar comes to the faid meridian. 
Look for this time in the left hand column of the table, 
oppofite to which in the column of azimuth, under the 
proper latitude, you will have the true azimuth of the ftar 
at that time. 
If the time before the ftar comes to the meridian be lefs 
than 12 hours, its azimuth will be eafterly ; but if more 
than 12 hours, its azimuth will be wefterly. 
If the magnetic azimuth, and the true azimuth at the 
time of the obfervation, be both eafterly or both wefterly, 
their difference will be the variation of the needle. But 
if one be eafterly and the other weflerly, their fum will 
be 
