mels, he saw a star in Pisces not put down in any catalogue, which turned out to be Juno.

JUPITER 2, the largest of all the planets, is still higher in the system, being about 426,000,000 miles from the Sun; and going at the rate of 25,000 miles every hour in his orbit, finishes his annual period in eleven of our years 314 days and 12 hours. He is above 1000 times as big as the Earth; for his diameter is 81,000 miles; which is more than ten times the diameter of the Earth.

Jupiter turns round his axis in 9 hours 56 minutes; so that his year contains 10,470 days; and the diurnal velocity of his equatorial parts is greater than the swiftness with which he moves in his annual orbit; a singular circumstance, as far as we know. By this prodigious quick rotation his equatorial inhabitants are carried 25,920 miles every hour (which is 920 miles an hour more than an inhabitant of our Earth's equator moves in 24 hours), besides the 25,000 above mentioned, which is common to all parts of his surface by his annual motion.

Jupiter is surrounded by faint substances called belts, in which so many changes appear that they are generally thought to be clouds; for some of them have been first interrupted and broken, and then have vanished entirely. They have sometimes been observed of different breadths, and afterwards have all become nearly of the same breadth. Large spots have been seen in these belts; and when a belt vanishes the contiguous spots disappear with it. The broken ends of some belts have been generally observed to revolve in the same time with the spots; only those nearer the equator in somewhat less time than those near the poles; perhaps on account of the Sun's greater

heat near the equator, which is parallel to the belts and course of the spots. Several large spots, which appear round at one time, grow oblong by degrees, and then divide into two or three round spots. The periodical time of the spots near the equator is 9 hours 50 minutes. To those near the poles 9 hours 56 minutes. See Dr. Smith's Optics and Ferguson's Astron.

The four satellites of Jupiter, which were discovered by Galileo, may frequently be well seen with a telescope that magnifies 30 or 40 times. The third and fourth have occasionally been seen with the naked eye.

A remarkable provision is made in the system to secure to the planet the benefit of his satellites. When Jupiter is deprived, at the same instant, of the light of the first and second satellites, or of the first and third, the remaining one of the three first cannot possibly be eclipsed at the same time; but is in such a point of its orbit as to give considerable light to the planet.

By means of the eclipses of Jupiter's satellites a method has been obtained for demonstrating that the motion of light is progressive, and not instantaneous, as was formerly supposed: it is found to travel from the Sun to the Earth, that is, ninetyfive millions of miles in about eight minutes.-Evid. La Place, Sys. du Monde.

JUBILEE. This word indicates the commencement of a certain period, and is thus described by Mr. Jamieson.-These are astronomical truths; but in nature the sign Aries has no part therein, its place being occupied by Pisces. More than two thousand years have passed away since the sign Aries, owing to the precession of the equinoxes, has ceased to open the astronomical year, as "Prin

ceps signorum et Ductor exercitûs Zodiaci." In more remote times the vernal equinox took place, and the year opened, when the Sun was in Taurus. But when astronomers and legislators agreed to reform the Calendar according to the new style, the Ram, with which the year commenced, was called Jubel; the Jubilee was proclaimed and the new year adopted, Herodotus tells us that once a year, on a certain day, at the festival of Jupiter Ammon, or the Sun in Aries, the people of Thebes, in Egypt, slew a ram. The Sun came into Aries on the 10th of the Jewish month Nisan. An annual feast was then celebrated, and a male ram was slain, to commemorate the deliverance from Egypt. At the period of the flight from Egypt the vernal equinox took place, when the Sun was in Aries.

Some connection has been supposed between the Pascal Lamb, or Easter offering, and the entrance of the Sun into the sign of the Ram. In p. 368 of Oedipus Judaicus, Sir William Drummond endeavours to prove that the feast of the Passover was instituted to celebrate the transit of the equinox from Taurus to Aries, which would happen in the lapse of time by the precession of the equinoctial points; just as now the equinox has really got into Pisces, though it is called the first point of Aries. That at a period not very remote from the institution of the Passover, Taurus was the sign of the vernal equinox, there can be no doubt. See TAURUS; also HYADES.

LATITUDE and LONGITUDE or distance in de grees and minutes from the equator, and from Greenwich Observatory.