MADE USE OF IN ASTRONOMY.

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Phases, the several appearances of the moon and planets,according as a greater or less part of their illuminatedhemispheres are presented to our sight.

Phoenix, a southern constellation, consisting of thirteenstars.

Phosphor, a name given to Venus when she is a morn-ing star.

Procyon, a fixed star of the second magnitude, in theconstellation Canis Minor.

Pisces, the Fishes, a zodiacal constellation, consisting ofa hundred and ten stars.

Pisces volans, the flying Fish, a southern constella-tion, consisting of seven stars.

Planets, (Primary,) those bodies, in our system, thatregard the sun as the center of their motions ; the num-ber of which is seven, Mercury , Venus $, theEarth ©, Mars <?, Jupiter A, Saturn h, and theGeorgium Sidus.

Plane, in astronomy, is frequently used for an imaginarysurface, which is supposed to cut and pass throughsolid bodies ; and in this sense we are to understand theplane of a planet’s orbit.

Planetarium, an instrument made use of for showingthe phænomena of the planets; see Plate 20.

Pleiades, seven remarkable stars in the constellationTaurus.

Polar Circles, two small circles of the sphere, twenty-three degrees and a half distant from the poles: thatabout the north pole is called the arctic circle, and theone about the south pole the antarctic circle.

Pole Star, a star of the second magnitude, in the tail ofthe Little Bear; so called from its being situated nearthe north pole of the world.

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Poles