PHYSICAL anv LITERARY. tog 
‘from noon to 6 hours, affuming 10000 
for radius, or the horiz. par. »4@-. The 
equation to be fubtracted from the appa- 
rent femid. © needs only be calculated 
for every 10th degree of longitude, and 
every half hour from noon to 6 hours, 
taking the mean femid. ©, 
13. Ir the given time from noon be 
more than 6 hours, fubtract it from 12 
hours, and the long. © from 12 figns ; 
and, for the remaining time and longi- 
tude, feek the intire parallax, and the e- 
quation for the femid. ©, changing its 
fign. 
14. SucH tables, tho’ conftructed for 
a particular latitude, may eafily be made 
to ferve for any other latitude. For the 
variations from the meridian parallaxes 
are always proportional to the cofine of 
Jatitude. And the meridian parallax, 
whether of long. or lat. is made up of the 
fum or difference of two parts; the firft 
of which is proportional to the fine, the 
fecond to the cofine of lat. Thefe two 
parts for the tabular latitude are found 
thus. To the given lon. © add 6 fens; 
and 
