96 Description and Use of the

Arctic and antarctic circles, orcircles of perpetual apparition andoccultation.

183. The largest parallel of latitude onthe terrestrial globe, as well as the largestcircle of declination on the celestial, thatappears entire above the horizon of anyplace in north latitude, was called by theancients the arctic circle, or circle of perpe-tual apparition.

Between the arctic circle and the northpole in the celestial sphere, are containedall those stars which never set at that place,and seem to us, by the rotative motion ofthe earth, to be perpetually carried roundabove our horizon in circles parallel to theequator.

The largest parallel of latitude on theterrestrial, and the largest parallel of decli-nation on the celestial globe, which is en-tirely hid below the horizon of any place,were by the ancients called the antarcticcircle, or circle of perpetual occultation.

This circle includes all the stars whichnever rife in that place to an inhabitant

of