means of influence skilfully, she may hope to succeed, certainly after one or two trials, in producing a dislike of contention, a desire to avoid it, and a resolution to sin in this respect no more. She may in the same manner go through the circle; fault after fault will be brought up, its nature and its consequences kindly pointed out, and those commands of God which bear upon the subject plainly brought to view. The interview may be closed by a short and simple prayer, that God would forgive, for Christ's sake, the sins they have confessed, and give them all strength to resist temptation during the coming week. Such an exercise, if managed as every kind and faithful mother can manage it, will succeed. The children will go away from it with consciences relieved, in some degree, from the burden of sin; they will look back upon it as a serious but happy interview, and will feel, though a wise mother will not try to draw from them an expression of that feeling, that it is a happy thing to repent of sin and to return to duty. I asked my readers, at the outset, to imagine the scene. but in fact it is not an imaginary scene. In substance it is reality.

I only offer it, however, as a specimen. If repeated in exactly this form every sabbath, the sameness might become tiresome. The idea which I mean to convey is, that the heart must be reached, and the progress of improvement must be advancing, or the object of the sabbath is lost. Unless you are improving, and elevating, and advancing your characters, discovering your faults and correcting them, learning God's will as it applies to your own conduct, and confessing and forsaking your sins; unless you are doing such work as this, you cannot be keeping the sabbath-day.

SKETCHES IN ASTRONOMY.

COMETS.

THE Comets are luminous bodies which at first scarcely perceptible, augment in size and velocity as they approach the sun, then diminish, and finally disappear. They are not so bright as the planets, but are accompanied by a nebulous (i. e. cloudy) appearance, which increasing, sometimes terminates in a train of considerable length, and of a substance extremely thin, since the stars are seen through it. This appearance, named the tail of a comet, is seen to issue from them in a direction opposite the sun, and increases as the comet approaches that luminary, decreases as the comet departs from the sun, and then gradually disappears.

The appearance of comets followed by these trains of light, has for a long time terrified mankind, always agitated by extraordinary events, of which the causes are unknown. The light of science has dispelled these vain fears; no longer do we look upon the approach of comets as a herald of war or pestilence. Many of them are found to obey laws similar to those which bind together in a system the planetary bodies; their return has been predicted, and the prediction has been verified; we conclude, therefore, that by these laws the motions of all the comets are regulated. The motions of at least one hundred have been computed, and it has been supposed that there are at least a thousand belonging to our system. The greater part of these are telescopic comets, or can be seen only by a powerful instrument. Dr. Herschell mentions six that have been discovered by his sister, and five by

himself. It is not clearly ascertained whether they have any solidity; some of them certainly have not; some of those observed by Dr. Herschell were so thin that the stars were seen through them, and he considered them merely as a collection of vapours condensed about a common centre.

In 1744, a comet was observed, and half its disk only appeared illuminated. If this observation was correct, it would prove that they, (or at least some of them,) like the planets, are opaque bodies, and derive their light from the sun. In 1811, Sir William Herschell observed a small luminous point in the centre of the comet, which he supposed was its disk.

The most satisfactory proof of their having solid nuclei would be by observing their passage over the sun's disk. Such an event took place in 1827. Unfortunately the sun was hid by clouds in this country; but it was observed at Marseilles, and no spot was seen upon the face of the sun, which evidently shows that this comet was transparent.

The appearance of one comet, that of 1680, has been several times recorded in history. The time which it occupies in its revolution is 575 years. Its tail was of immense length: at Constantinople, when the comet was in the horizon, the extremity of its tail was in the zenith. Two such comets in opposite points of the horizon, would, if their tails were both projected upwards, form by their means a luminous arch extending over the whole heavens. It approached the sun within one-sixth part of the diameter, and it recedes to a distance equal to 138 times the distance of the sun from the earth, or to nearly thirteen thousand millions of miles.

Dr. Halley's comet is another remarkable one, and derived its name from his having predicted its return. It had been observed with accuracy in 1607 and 1682; and a comet had been noticed in 1305, 1456, and 1531. Halley supposed that this was one and the

same comet, and he predicted its return in 1759, in which year it really appeared. This comet again became visible in 1835, its period being about seventy-six years.

Another comet was observed in 1770, and its path computed with great care; it was expected to return in five years and a half, but it has never been seen since. It was, however, remarked that the computed orbit passed very near Jupiter, and that the attraction of that vast planet so changed the path of the comet, that when it returned to the sun, it did not approach us, or it, sufficiently near to be visible. This comet is remarkable for having approached nearer the earth than any other comet that has been observed, and by that means enabled us to ascertain in some degree its mass or quantity of matter.

Laplace, the great French astronomer, computed that, had it been equal in size to our earth, it would have shortened the length of the year by one-ninth of a day. Now, it has been ascertained, by computations on the Greenwich observations, that the length of the year has not been changed by any perceptible quantity, and thence Laplace concluded that the mass of that comet was less than 1-5000th part of the mass of the earth.

From these and other circumstances, it seems probable that the comets are in general inconsiderable, and can produce no effect upon our system; and that even if one of them came into collision with the earth, the mischief, if any, would be local, and the balance of the earth speedily restored.

The nebulous, or cloudy part of comets, is said to diminish every time they return to the sun, so that after frequent returns, they may lose it altogether; and if the substances of which they are composed evaporate, they will disappear and be seen no more.

With respect to the tails of comets, little can be said that is satisfactory. Sir Isaac Newton supposed that

they arose from a thin vapour sent out from the comet by the heat of the sun.

Sir William Herschell, after having stated that it is probable that many of them are a mere collection of vapours, says, "This throws a mystery over their destination, which seems to place them in the allegorical view of tools, probably designed for some salutary purposes to be wrought by them; but whether the restoration of what is lost in the sun by the emission of light may not be one of these purposes, I presume not to determine.'

Comet is derived from a Greek word signifying the hair.

HONESTY. In the last war in Germany, a captain of cavalry was out on a foraging party. On perceiving a cottage in the midst of a solitary valley, he went up and knocked at the door: out came a Hernouten with a beard silvered by age. 66 'Father," said the officer, "shew me a field where I can set my troopers a foraging." The old man walked before, and conducted them out of the valley. After a quarter of an hour's march, they found a fine field of barley, but they went on and at the distance of about a quarter of a league farther, they arrived at another field of barley. The troop immediately dismounted, cut down the grain, trussed it up, and remounted. The officer upon this said to his conductor, "Father, you have given yourself and us unnecessary trouble: the first field was much better than this." 66 'Very true, Sir," replied the good old man, "but it is not mine."