why a stone or a ball, or anything thrown up into the air, would fall down again to the ground.

After much thought and study upon this apparently trifling subject, he discovered the cause; and he also found out that the same cause which made the apple fall, also causes the earth to move around the sun, the moon to travel about the earth, keeps the heavenly bodies in their places, causes the regular rise and fall of the tides of the ocean, and gives us those agreeable varieties in the seasons known by the names of spring, summer, autumn, and winter.*

I could point out to you many important discoveries that have been made by thinking men, but enough has already been said to convince you of the importance of learning to think. I shall close the subject by relating to you the manner in which a school exercise was performed by a little girl, only thirteen years of age, a few years ago.

The teacher was a man who was very anxious to make his pupils think. He had talked to them much about it, and was constantly studying out new ways, as well as practicing those to which he had been accustomed, to induce his scholars to exercise their thoughts.

He one day proposed to them to write a composition on a subject which at first appeared very difficult. His object was to make them think; and how he succeeded you shall learn by the following recital:

He told them that, about seventeen hundred years ago, there were two large cities, called Herculaneum and Pompeii, situated near the foot of Mount Vesuvius; that a volcano burst out from the top of the mountain, and, in one night, poured out such an immense mass of fire, flame, ashes, cinders, and red-hot liquid matter, called lava, that it completely covered over both of these large cities, and buried them to the depth of many feet under its surface,

Nearly seventeen hundred years rolled away, and even the spot where those cities stood was forgotten. Houses were built, trees grew, and gardens were planted over them.

About seventy years ago, as some labourers were digging a well, they came, to their great surprise, to the top of a house deep in the ground.

This discovery induced them to dig further in different directions,

*This great discovery of Sir Isaac Newton is called the attraction of gravitation. It is the fundamental law of nature. Every particle of matter attracts and is also attracted by every other particle of matter; and this attraction is proportional to its quality and distance. As the earth itself is the largest and nearest of all the bodies with which we are practically acquainted, everything within the sphere of its attraction, when unsupported, must fall to the earth, that is, obey its attraction. The science of astronomy makes us acquainted with those heavenly bodies which, being larger than the earth, influence the motions of the earth. and produce all those effects which have been described as resulting from the universal law gravitation, discovered by Sir Isaac Newton.-Parker.

until large parts of these ill-fated cities were brought to light, and the dead bodies of many of the unfortunate inhabitants who had been buried alive were also discovered.

When Pompeii was discovered, a barber's shop was found, furnished with materials for dressing hair. "Now," said the teacher to his pupils, "I wish you to think, and write on paper what you can find out with regard to the inhabitants of this ancient city, from the fact that a barber's shop, with materials for dressing hair, was discovered in it."

How the pupils thought upon the subject, and how the exercise required by the teacher was performed, you shall learn in the next lesson, which is the exercise itself of the little girl spoken of, written upon that very occasion,*

POMPEII.

"When Pompeii was discovered, a barber's shop was found, furnished with materials for dressing hair. From this circumstance, what may be inferred with regard to the attainments of this city in the arts and sciences?"

AMONG savage nations we find no distinct trades or occupations. Each person prepares such articles only as are necessary for his own use, such as his tenement, his tools, and his clothing,— without receiving assistance from others. Therefore, if the old maxim, "Practice makes perfect," be true, all work must be very rudely and incompletely furnished, as each person would be a learner in every different article he needed.

The principal food of the savage consists of such fruit and vegetable as the earth produces spontaneously, in addition to what is easily obtained from the sea and the forest. The skins of beasts, taken in hunting, form the clothing of the savage. The females of such nations are almost universally treated as slaves, having the most severe portion of the labour assigned for their performance.

What a different picture did Pompeii present from the dwelling of a savage, when overwhelmed by the burning lava, and buried for so many ages in oblivion! A barber's shop, with implements for dressing hair, argues an improved state of the arts.

In the first place, the principal art learned by the ancients was war. Now, their passion for this must have subsided in some degree, and a pacific disposition have pervaded the inhabitants of Pompeii,

This is a true story, and the next lesson is the piece just as it was written by the pupil.-Parker.

ere their attention would have been directed to improvement in any thing else. A wise legislature would likewise have been required to frame laws, and magistrates to administer justice, by enforcing them.

Again, a state of undisturbed peace must always continue some length of time, in order that the sciences may flourish; as political commotions, whenever they exist, usually occupy the first place in the minds of a nation. Distinct and separate trades must have had existence in Pompeii, otherwise there would have been no such thing as a barber's shop. Doubtless there were a great variety of trades, as that of a barber is one of the least useful.

In order to the erection of a shop, farmers would be needed to cultivate the earth, that those engaged in other occupations might be supported. Mines must have been discovered and their uses determined. Articles of iron must have been made by blacksmiths, after the iron had been prepared by those whose business it was to prepare it.

Knives and other cutting instruments would require a cutler, after the steel had been prepared from iron by another class of persons. Again, after the timber had been taken from the forest, and in some measure prepared, a carpenter would be needed to build the house.

To heat his curling-irons, the barber must have a chimney, which would require a mason; and the mason must have bricks and mortar with which to erect it. The clay of which bricks are made must be moulded into the proper shape, and then burnt sufficiently hard to be used. The mortar consists of lime, sand, and hair.

The art of making glass must have been discovered, otherwise the barber's shop would have been rather too dark to dress hair with much taste. Glass, besides other materials, would require a particular kind of sand and pearlash. Pearlash requires much labour in its extraction from ashes. A diamond must have been obtained to cut the glass, consequently precious stones must have been in use.

Again, a glazier would have been needed to set the glass in window-frames. For that purpose he would have wanted putty. One of the materials of putty is linseed oil. This oil is extracted from the seed of flax.

Now, it is not probable that flax was cultivated merely for its seed; therefore, we may reasonably suppose that it went through all the various operations requisite for making it into cloth. The loom and wheel used in manufacturing cloth must have required much skill and workmanship in the artist, and much genius in the inventor. And if cloth were made from flax, might it not also be made from other productions of the earth?

As mines were common, and men were engaged in so many dif ferent arts, it is not likely that they remained without the convenience of coined money. The existence of a barber's shop also argues that balls and public amusements were common; otherwise there would have been no occasion for a barber; as most persons, by spending a few moments, can dispose of their hair very decently.

It also argues that there were a class of persons who, being possessed of wealth, could spend their time in pursuit of pleasure. If the various mechanical arts had arrived at such a degree of perfection, is it not probable that the commerce of Pompeii had become quite extensive? If so, vessels must have been employed to transport articles from place to place.

For the management of vessels, something of navigation and astronomy must have been known. If paint was in use, and vessels were painted, as was doubtless the case, chemistry must have been understood in a degree. Pompeii, therefore, at the time of its overthrow, was nearly as far advanced in the arts and sciences of civilised life as we now are. Yet the inhabitants were in a state of heathenish superstition, without any correct system of morals or religion; and, compared with the United States of America, were a miserable people. This, then, should excite the gratitude of every inhabitant of ourhappy land.

OBSERVATION.

THE light of the understanding is far more valuable to us than the common light of day. It is our own—a light within us-nothing can cloud it; darkness itself cannot hide it, if it be once kindled in the proper manner, and to the proper extent. But though its illuminating influence be within, we must at first light it up from without; and though it be the candle of the mind, it can only be lighted by knowledge obtained through the medium of those senses with which our all-bountiful Creator has furnished us. The exercise of those senses is OBSERVATION; and that is the fountain of all knowledge, and the original source of all pleasure, whether that which we immediately know or enjoy be or be not present to the senses. What we thus obtain, is unalienably vested in us for the whole period of our lives. That which we have in our coffers, may decay through time, or be destroyed by accident; or it may be taken from us, or we from it and that which is told to us by others, may be false, or we may forget it by the weakness of the impression it made; but that which we see. with our own eyes, or otherwise perceive with our own senses, is proof against accidents, against time, and against forgetfulness.