Celejlialand terrestrial Globes. 281

But remember, that either the autumnalor vernal equinoctial colure must first beplaced under the graduated fide of thestrong brass meridian before you -observethe hour, each of these being marked uponthe equator with the hour XII.

The string in this last cafe being movedinto the plane of the fun, corresponds withthe true hour circle, and consequently givesthe true hour.

jdly, Without any stile at all.

319. Every thing being rectified as be-fore, look where the shade of extuberancycuts the equator, the colure being un-der the graduated side of the strong brassmeridian, and you obtain the hour in twoplaces upon the equator, one of themgoing before, and the other following thefun.

Note. If this shade be dubious, apply apin or your finger as before directed.

The reason is, that the shade of extu-berancy being a great circle, cuts the equa-tor in half, and the fun, in whatsoeverparallel of declination he may happen to

be,