2 j6 Description and Use of the

Stars of the first magnitude, according toPtolemy, rife or set heliacally, when theyare 12 degrees distant from the fun: that is,when the star is rising, the fun must be de-pressed in the perpendicular below the hori-zon 12 degrees, that the star may be farenough from the fun’s rays to be seen be-fore he rises.

Stars of the second magnitude requirethe sun’s depression thirteen degrees, andthose of the third magnitude fourteen de-grees, &c.

The nlanazil al kamer of the Ara-bian astronomers, * from UlughLeigh, published at Oxford 1665.

304. The manazil al kamer of the Ara-bian astronomers, are XXVIII, they are socalled, i. e. the mansions of the moon, be-cause they observed the moon to be in ornear one of these every night during hermonthly course round the earth: they arethese that follow, to which upon the globethe Arabian characters are affixed, but omit-ted here for the want of an Arabian type.

I. Al

* See the Rev. Mr. Costard’s History of Astronomy, p. 19.