In the year 388, he returned to his native country, and, three years afterwards, was chosen Bishop of Hippo. Augustine was a judicious divine, and the most voluminous writer of all the Fathers. He died in 430, at the age of 77.

29.-JOHN BAPTIST BEHEADED.

This day was formerly denominated Festum Collectionis Sancti Johannis Baptistæ; or the feast of gathering up St. John the Baptist's relics; but afterwards, by corruption, Festum Decollationis, the festival in remembrance of his being beheaded. His nativity is celebrated on the 24th of June, which see; and also T.T. for 1817, p. 164, for some lines on St. John, by Cottle.

Astronomical Occurrences

In AUGUST 1819.

THE Sun enters Virgo at 15m. after 1 in the morning of the 24th of this month; and he rises and sets as in the following Table, during the same period.

TABLE

Of the Sun's Rising and Setting for every fifth Day. August 1, Sun rises 20 m. after 4. Sets 40 m. after 7

Equation of Time.

7

58

48

To the time as indicated by a good sun-dial, add the quantity in the following Table answering to the given day; and it will give the time that ought to be shown by a well regulated clock at the same moment.

TABLE.

m. s.

August 1st, to the time by the dial add 6 1

Jay

6th, 11th, 16th,

21st,

- 26th,

31st,

First Quarter 28th,

13

13

6

9

3 afternoon.

Moon's Passage over the Meridian.

If the weather be favourable, the Moon may be observed to pass the first meridian at the following times during this month: viz.

August 1st, at 53 m. after 7 in the evening.

56

2d,
3d, 2
4th,

8

22d, 24. 23d, 12 24th,

0

51

25th,
30th, 50
31st, 55

Phase of Venus.

August 1st {Dark part

Enlightened part

Eclipses of Jupiter's Satellites.

The following are the eclipses of Jupiter's first and second satellites, which are visible at the Royal Observatory during this month: viz.

Mercury will attain his greatest elongation on the 10th of this month, and appear stationary on the 24th. Jupiter will be in opposition at 15 m. past 2 in the afternoon of the 5th. The Moon will be in conjunction with Saturn at 47 m. after 2 in the morn

ing of the 9th; with ß in Taurus at 29 m. past 7 in the morning of the 15th; with Pollux, at 2m. after 8 in the evening of the 17th; and with a in Scorpio, at 23 m. after 8 in the evening of the 28th.

On the EFFECTS of GRAVITATION.

When the powers of reason, borne on the wings of science, launch into the boundless regions of physical research, the mind is soon convinced that Infinite Wisdom has placed first principles entirely beyond its grasp, and submitted only the laws by which they act to its investigation. By the former, he has opposed an effectual barrier to the arrogant curiosity of the perverted mind; and, by the latter, afforded unlimited scope for the exercise and progressive improvement of the intellectual faculties of the human mind. This sentiment applies with peculiar force to the subject of gravitation, the cause of which has hitherto eluded the most daring flights of genius; while its phenomena have constantly arrested the attention and excited the admiration of the students of nature in all ages of the world.

By gravitation, philosophers understand that power of attraction which every particle of matter exerts upon every other particle at finite distances from each other. As bodies, whatever their nature and magnitude may be, are only aggregated particles, the same attraction takes place proportionally between them; and gravitation, therefore, becomes the most universal law of the material world. It is by this power that bodies retain their forms; that the component parts of the earth and the other planets are not dissipated in the boundless regions of space; that terrestrial bodies, when unsupported, descend to the earth; that the planets and their satellites are retained in their orbits; and that the solar system itself maintains its place in the universe. This is the elevated mount to which the philosopher is conducted by the phenomena of nature. It is this point

on which he takes his stand, and is enabled not only to explain present appearances, but to predict the future situations of the heavenly bodies with an accuracy which appears little less than miraculous, to those who are unacquainted with this great law of the material world. To some persons, indeed, it seems as if the Deity had unveiled the secrets by which he governs the universe. Only the effects of this power, however, are perceptible to our senses, while the Great Agent which produces them, and thus, as it were, gives life and motion to inanimate beings, is an invisible principle.

On considering the influence of this invisible and powerful agent, the mind is immediately struck with the imperfection of physical knowledge prior to the moment when NEWTON, in one of his contemplative modes, was roused from his reverie by the falling of an apple, a fact which had been exhibited for thousands of years, and might have been for ever observed by ordinary minds, without leading to any important conclusion. But when the genius of Newton was once brought to bear upon this point, that which for ages had been impenetrable became less impervious, till, by a chain of reasoning, as simple as it was accurate, he laid the magnificent scene of nature open to our view, and unveiled the law by which not only atoms but worlds are combined into one harmonious whole.

All the phenomena of attraction, as far as they have yet been the subjects of observation, or comprehended by the human mind, unite in proving that this power is exercised by every particle of matter, and that the law which regulates its intensity is that of the inverse square of the distance, or, in other terms, the attractive power with which any body acts upon another is directly as its mass and inversely as the square of its distance: thus if F denote the force of attraction, M the mass or quantity of matter in

any body, and D its distance from any other body; and if f, m, and d, denote the same for any other body, we have

From this general proportion, the ratio of either the masses or the distances of bodies is easily found in terms of each other; for by multiplying by D1 and d', we have

M: m :: FD2 : fd2.

And again, by dividing the terms of this last proportion by F and ƒ, and taking the square roots of the quotients, we shall also have

Astronomers and philosophers have demonstrated this law from the following considerations:-1. By observing and comparing the effects of gravity at the top and bottom of mountains; 2. By the descent of bodies near the surface of the Earth compared with that of the Moon in her orbit in the same time; 3. By the comparison of the arcs described in the same time by all the planets revolving round the Sun, and the satellites about their primaries; 4. By the ratio of the squares of the times of the planetary revolutions to the cubes of their mean distances; 5. By the constant ratio between the areas described by the radius vector of each planet and the times of their description; 6. By the motions of the planets in elliptical orbits, and by the direction of gravity towards one of the foci of the ellipse. As the nature of our work necessarily precludes us from exhibiting the proofs themselves from which this great law is derived, we