The _Earth_,--its diameter 7970 miles; distance of orbit from the sun 95,173,000 miles; revolves on its axis once in 24 hours; performs her annual period round the sun in the same time the sun completes his revolution; hourly equatorial and progressive motion in orbit 80,295 miles. The _Moon_ is a satellite to the earth; her diameter is 2180 miles; her diurnal rotation on axis is performed in 29 days, 12 hours, 44 minutes; she performs her annual revolution round the sun in precisely the same time as does the earth, her superior planet; her motion in orbit per hour is 22,290 miles. _Mars_,--his diameter is 5400 miles; distance from the sun, 145,014,148 miles; annual period round the sun 671 days, 17 hours; diurnal rotation on axis 19 days, 12 hours, 44 minutes; hourly motion in orbit 55,287 miles. _Jupiter_,--his diameter 94,000 miles; distance from the sun 494,990,976 miles; annual period in 11 years, 314 days, 18 hours; diurnal rotation on axis 9 hours, 56 minutes; hourly motion in orbit 29,803 miles. _Saturn_,--his diameter 78,000 miles; distance from the sun 907,956,130 miles; annual revolution in orbit 22 years, 167 days, 6 hours; hourly motion in orbit 22,101 miles. It should be observed that Jupiter has four moons, or satellites, with a large and very luminous belt at a great distance from his surface. Saturn also has seven moons, with a very luminous ring about 21,000 miles broad, from its uppermost to its undermost edge; and about the same distance from its surface. _Georgium Sidus_,--the distance of the orbit from the sun, 1,758,000,000 miles; annual revolution 28 years, 289 days; diameter 56,726 miles; has two satellites, or moons. About 1801, 2, and 4, there were discovered three other small planets in the system of the sun, called _Vesta_, _Juno_, and _Pallas_. The fixed stars composing the _Zodiacal Signs_, are divided into twelve constellations, one to each month; which asterisms were discovered by Flamstead to consist of the following number of stars to each: _Aries_, the Ram, 66; _Taurus_, the Bull, 141; _Gemini_, the Twins, 85; _Cancer_, the Crab, 83; _Leo_, the Lion, 95; _Virgo_, the Virgin, 110; _Libra_, the Scales, 51; _Scorpio_, the Scorpion, 44; _Sagitarius_, the Archer, 69; _Capricornus_, the Goat, 51; _Aquarius_, the Water-Carrier, 108; _Pisces_, the Fishes, 113. A comparative idea of the extent of the works of Omnipotence may be perhaps collected, on our being informed, that the sphere where the fixed stars appear, is presumed to be placed far beyond the most remote planetary orbit; and that some of them are supposed to serve as suns to illumine other systems, or worlds, to us unknown. NAVIGATION.