and should have an orbit more analogous in eccentricity and inclination than any of the smaller fragments to the other planets of the system. As far as the diameters of the new planets have been measured, the theory is most strikingly verified by observation. The observations of Schroeter make Juno considerably less than Ceres; and though the diameter of Vesta has not been accurately ascertained, yet the intensity of its light, and the circumstance of its being sometimes distinctly visible to the naked eye, are strong proofs that it exceeds in magnitude both Pallas and Juno.

The resemblance between the two lesser fragments, Pallas and Juno, in their magnitudes, and in the extreme eccentricity of their orbits, would lead us to anticipate similar resemblances in the position of their nodes, in the place of their perihelia, and in the inclination of their orbits; while the elements of Ceres and Vesta should exhibit similar coincidences. Now it is found that the inclination of Ceres is 10', and that of Vesta 7°; while the inclination of Juno is 21°, and that of Pallas 34°; the two greater fragments having nearly the same inclination, and keeping near the ecliptic, while the lesser fragments diverge from the original path, and rise to a great height above the ecliptic, and far above the orbits of all the other planets in the system. If it shall hereafter be found that Vesta is one of the smaller fragments, we shall then be able to account for its position with regard to Ceres, and for the small inclination and eccentricity of its orbit, by supposing the planets Ceres, Pallas, and Juno, to have diverged in the same plane, and nearly at right angles to the ecliptic, whilst Vesta diverged from the direction of the original planet, in a plane parallel with the ecliptic. This opinion is strongly confirmed by the fact, that the orbit of Vesta is nearer to the Sun than any of the orbits of the other three fragments. In the position of the nodes, we perceive the same coincidence; the orbits of Pallas and Juno cut the ecliptic in the same point, and the nodes of Ceres and Vesta are not far distant.

+

If all the fragments of the original planet had, after the explosion, been attracted to the larger fragment, it is obvious that they would all move in the same orbit, and consequently have the same perihelion. If the fragments received a slight degree of divergency from the explosive force, and moved in separate orbits, the points of their perihelion would not coincide, and their separation would increase with the divergency of the fragments. But since the several fragments partook of the motion of the primitive planet, the angle of divergency could never be very great, and therefore we should expect that all the perihelia of the new planets would be in the same quarter of the heavens. This theoretical deduction is most wonderfully confirmed by observation; for it is found that all the perihelia are in the same semicircle, and all the aphelia in the opposite semicircle: the perihelia of the two larger fragments, Ceres and Vesta, being near each other, as might have been expected, while there is a similar proximity between the perihelia of the lesser fragments, Pallas and Juno.

These singular resemblances in the motions of the greater fragments, and in those of the lesser fragments, and the striking coincidences between the theory and observation in the eccentricity of their orbits, in their inclination to the ecliptic, in the position of their nodes, and in the places of their perihelia, are phenomena which could not result from chance; and which concur to prove, with an evidence amounting almost to demonstration, that the four new planets have diverged from one common node, and have therefore composed a single planet.

We may proceed to consider other phenomena that may be supposed to accompany this great convulsion. When the cohesion of the planet was overcome by the action of the explosive force, a number of little fragments, detached along with the greater masses, would, on account of their smallness, be projected with very great velocity; and being thrown beyond the attraction of the larger fragments, might fall to-:

wards the earth when Mars happened to be in the remote part of his orbit. These fragments will evidently be thrown off with the greatest velocity, and will always be separated from, those parts which formed the central portions of the primitive planet. The detached fragments, therefore, which are projected beyond the attractive force of the larger masses, must always have been torn from the central parts of the original body. When the portions which are thus detached arrive within the sphere of the earth's attraction, they may revolve round that body at different distances, and may fall upon its surface, in consequence of a diminution of their centrifugal force; or, being struck by the electric fluid, they may be precipitated on the earth, and exhibit all those phenomena which usually accompany meteoric stones. Hence the reason why the fall of these bodies is sometimes attended with explosions, and sometimes not, and why they generally fall obliquely, and sometimes horizontally; a direction which they could never assume, if they descended from a state of rest in the atmosphere, or had been projected from volcanoes on the surface of the earth.

Another argument in favour of this theory has been taken from the density of the new planets, compared with that of the meteoric stones. For since the fragments of the large planet, which are supposed to be meteoric stones, must have been detached from the central parts of the primitive planet, the specific gravity of meteoric stones ought to exceed the average density of the planet... The density of the whole earth is 4.8, but the density of Schehallien, a mountain in Scotland, is but 2.7; of course, the density of the central parts of our globe cannot be less than 7 or 8, in order to make up the mean density. Now, the density of the new planets is found to be nearly 2;

'See Sir John Pringle's excellent Discourse on the Attraction of Mountains,' 1783.

Cc

and, following the proportion just stated in the case of the earth, we might expect that the average density of meteoric stones should be about 3.2, which happens to be the exact specific gravity of the greatest number of these bodies. This coincidence is truly surprising; and, when taken in connection with the evidence arising from the form and position of the orbits of new planets, gives a probability to the theory which no other hypotheses can claim.

The Sun's rising and setting at intervals this month will be as follows::

1st, Sun rises 12 m. past 6. Sun sets at 48 m. past 5

Saturday,
Tuesday, 11th,
Friday, 21st,
Monday, 31st,

32

Equation of Time.-The following table will enable the reader to adjust his clock or watch to true or equal time, by subtracting a certain number of minutes and seconds from apparent time:

m. S.

1st, from the time on the dial SUBTRACT 10 11

Saturday,

Thursday, 6th,

Tuesday,

11th,

Sunday,

16th,

Friday, - 21st,

Wednesday, 26th,

Monday

31st,

The Sun enters the sign Scorpio at a minute after I in the morning of the 24th.

:

The Moon enters its last quarter at 58 m. past 11 in the forenoon of the 6th. The new Moon, or change, will be at 51 m. past 10 in the forenoon of the 13th it enters its first quarter at 49 m. past 8 in the morning of the 21st, and is full at 16 m. past midnight of the 28th. The time of the Moon's rising, the first six days after the full in September, will be as follows:

On the 1st day of the month, the Moon will eclipse the star μ Ceti: the immersion will be 40 m. past 10 in the evening, and the emersion at 41 m. past 11; in the former case, the star will be near 5 m. south of the Moon's centre, and in the latter 84 on the same side. On the 30th, there will be also an eclipse of the 188, of which the immersion will be at 15 m. past 1 in the morning, and the emersion 21 m. past 2 at the immersion, the star will be 4' south of the Moon's centre, and at the emersion it will be 9' on the same side.

On the 20th, at 33 m. past 5 o'clock in the morning, there will be an eclipse of Jupiter's second satellite.

VIEW OF THE SOLAR SYSTEM.

Of Jupiter.

Jupiter is, with the exception of Venus, the most brilliant of all the planets: he is the largest body in the whole solar system, excepting the Sun, around which they all revolve, his diameter being eleven times greater than that of the earth, or nearly 90,000 English miles in length. He moves from the west to the east in a period of 4332 days, or in 11 years 318 days. Before he comes into opposition, and, when distant from the Sun, in the course of its revolution, about 115°, his motion becomes retrograde, and increases in swiftness till he comes in opposition. The motion then becomes gradually slower, and is direct when the planet advances within 115° of the Sun. The direction of the retrograde motion is about 121 days, and the arc of retrogradation described is about 10°. With respect to all the superior planets, the farther they are from the Sun, the less is the arc of retrogradation, but the longer time is taken in describing it; for, were the distance of the planets indefinitely great, the arc of retrogradation would be extremely small.