132 Description and XJse os the

We {hall proceed to exemplify these par-ticulars at the times of equinox and solstice.

PROBLEM XVIII.

The time of equinox.

222. The sun has no declination at thetimes of equinox, consequently there mustbe no elevation of the poles.

Bring the day of the month on the back-side of the strong brass circle, in which thefun enters the first point of Aries or Libra,into the plane of the broad paper circle,and then the two poles of the globe will bein that plane also; and all those circles whichare parallel to the equator will cut the planeof that broad circle at right angles, and theglobe will then represent a right sphere.

If you now turn the globe from west toeast, it will plainly appear, that all placesupon its surface are twelve hours above thebroad paper circle, and as many below it jwhich strews, that the nights are equal to thedays to all the inhabitants of the earth j that,is, they are illuminated by the fun’s raystwelve hours : Whence these are called theequinoctial seasons, two of which occur in

every