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Man's DEVELOPMENT BY EDUCATION.

shot their arrows of light into human eyes as they do now. Why then were the power and glory of God so long belittled and vilified by the universal conviction that the sky arched itself but a few furlongs over our heads, and that all the wealth of the heavens, as was supposed in the time of Ptolemy, consisted in but a thousand stars? Why were the moons of Jupiter, the fluid rings of Saturn, the orbs of Uranus and Neptune, and the vast islands of light that move in their appointed spheres, through the immensity of space, whose beams with all their lightning speed are supposed to have been millions of years in reaching our earth—why were all these grandeurs and glories of Jehovah a nonentity to man?

There they stood, rank behind rank, in vaster circles, refulgent through all the ages as at present, a fit frontispiece to the volume of God's goodness and power ; but human eyes beheld them not, and human hearts were not lifted up to God by their majesty and splendor. The race waited for the great minds that should lay open these starry depths of heaven. The minds came, the depths were laid open, and the celestial light blazed down upon us to attest the power and beneficence of the Creator, and again to make all the sons of God shout together for joy.

It is so in regard to all things. In all philosophies, in all theologies, in all principles of whatever kind, there are now just as many absolute truths in existence as there ever will be, There they exist, more valuable to man than zones of gold, sweeter in affections than unfallen Eden, sublimer than any Patmos yet revealed to man ; and the problem which we have to work is, to prepare the men who can discover these more glorious truths, just as men prepared the telescopes by which the pre-existent stars were discovered. The truths whose shining faces no mortal hath yet seen are no less real, they will be no less freighted with blessings when they come than those by which we have been already gladdened and improved. But they lie beyond the frontier of our present knowledge, and therefore, as yet, are useless to mankind.

Man wanted more labor than he could himself perform, and then, not by superior strength, but by superior mind, he domesticated and trained the animals, the ox for strength, the horse for fleetness. These were not enough, and so he enslaved his fellow-man. But intellect saw mightier powers in the elements than in any muscles of beast or slave; and now gravitation strikes our blows in the ponderous hammer, and steam cleaves the billows, or rushes across the land to bear our burdens or ourselves.

MAN'S DEVELOPMENT BY EDUCATION.

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The winds once swept by the savage, useless as the fiery clouds they wafted on their bosom; but mind has trained them to bear the bark of the explorer to every part of the earth, and to waft the commerce of the world. The lightning once came only to terrify and blast; but now it executes costly embellishments in the shop of the artificer, and bears messages of intelligence and affection wherever the telegraphic wire is stretched. Man prepares and arranges a few wheels, and by His agents, of air and water and fire, God turns the machinery by day and by night, to supply our persons and dwellings with the fabrics of comfort and elegance.

To form the strawberry, the peach, or the grain of wheat, the elementary atoms of which they consist traverse continents, and como from every zone. By what we call the laws of chance, how few of these atoms would ever meet and mingle to form our nectarious fruits or our nutritious harvests ! But the agricultural art summons its infinitesimal hosts—the mineral from the earth, the

gases

from the air, the water from the clouds, the light from the sky-leads them through all the subtile and mysterious channels of vegetable growth, and elaborates them into all the golden harvests of the year. What fullness of granary and storehouse, what freights for ship and car, come from agricultural knowledge—that is, from mind—where onco the barrenness of earth and the barreness of ignorance spread a common solitude. * * *

God's heart is full of new mechanical and new physical blessings for the race. He only waits for the fullness of time when physiology and education shall produce the men with talent and genius worthy to be the medium of their transmission to mankind. God knew the weight of the atmosphere and the law of gravitation ; He saw this Western continent; He knew how books could be printed, how cloth could be woven by machinery, and how lightning would run through iron, as well in the time of Solomon and Socrates, as since ; but, in the order of His providence, He waited for Torricelli and Newton, for Columbus and Faustus, for Arkwright and Franklin, before He blessed mankind by the bestowment of that knowledge.

In the same way He waits for us, through a knowledge of the laws of physiology and education, and an obedience to them, to rear the new men for the new blessings. Man's ideas of the earth are yet to be as much changed by chemistry as his ideas of the heaven have been by astronomy. Chemistry will yet beautify the earth as much as astronomy has glorified the heavens.

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We have just got a foothold on the infinitude of God's knowledge and wisdom; just trod upon the outer verge of his illim, itable realms. No natural impediment forbids our turning what is now divine knowledge into human knowledge. We may ascend Pisgahs after Pisgahs, and enter Canaans after Canaans, yet forever see before us new Pisgahs to be ascended, and Canaans flowing with the milk and honey of a diviner wisdom to be made our own.

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POLARIZED LIGHT-ITS UTILITY.

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“ Immortal Amaranth” become,

With which the brow to twine;
And he who wears this coronal

A radiant star shall shine
In the new firmament of God

When the old hath passed away;
How glorious, then, this crown to win,

Which never knows decay.
ELMIRA, N. Y.

POLARIZED LIGHT-ITS UTILITY.

BY PROF. C. G. PAGE.

HEN an isolated principle or truth, in any branch of science, is

discovered, the question is immediately asked, Cui bono? quid utile ? of what use is it? Franklin answered this question for all time by asking another, viz.: “What is the use of a new-born babe ?', Of what use or importance to man was it that, in 1810, M. Malus discovered that the different sides of a ray of light are possessed of different properties in relation to the plane of its incidence? This is one of the most obscure of all scientific propositions, and yet we shall soon see how triumphantly the caviler is silenced, and how liberally even this little fountain has poured its treasures into the lap of art.

Without entering into the elucidation of the facts, we will enumerate them as they occur to us.

When glass is properly annealed, and of a good quality, it exhibits no change of colors when examined by polarized light. If the glass has not been properly annealed, the polariscope instantly detects the defect by the display of colors. The annealing of glass is expensive, and the manufacturer often slights this part of his work. Glass tumblers, pitchers, decanters, tubes, etc., not well annealed, break often upon the slightest scratch, or upon the sudden application of heat or cold. Glass tumblers will often crack when a piece of ice is left in them, and frequently break when set away by themselves, owing to some slight scratch which they might have received a week previous.

Following the directions laid down in treatises on polarized light, a few little plates of glass, or, what is better, a Nicol's prism and a piece of glass blackened on one side, will show the purchaser

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POLARIZED LIGHT-ITS UTILITY.

whether he is buying annealed glass or not. The Nicol's prism, or eye-piece, is a simple apparatus, costing from one to ten dollars, and so small that it may be carried in the vest pocket without inconvenience.

If a piece of annealed glass be pressed or bent, the arrangement of its particles becomes disturbed, but this disturbance does not manifest itself to the eye nor to the most powerful magnifier. But when viewed by polarized light, the whole internal commotion reveals itself in the most beautiful manner, and while the pressure is increasing, disruption seems inevitable, though all the while to the naked eye no sign of fracture or change is apparent. A beautiful feature in this experiment is, that it shows exactly in what direction fracture would take place if the pressure were sufficiently increased. Taking advantage of this property, model bridges and other structures have been made of glass; and when submitted to strain or pressure, the polarized ray discloses to the architect what neither the unassisted eye nor calculation could ever discover.

The quality of gems for jewelry is determined by polarized light. The quality of sugars and of many articles of commerce, and of woven fabrics suspected of adulteration, may be proved by polarized light. When you enter a picture gallery you are often cheated of a good view of some painting by the strong reflection of light from the varnish, and you may not be able to select a suitable position. Look at the picture through Nicol's eye-piece, and all this reflected light is at once obliterated, and you have a good position anywhere. It is the same when specular reflections interfere with the sight in viewing a landscape, or any distant objects.

Last, and not least, the mariner often detects, even at a great distance, shoal water or sunken rocks, by the color of the water ; but if the sun is shining, and the reflection from the waves is before him, he can see nothing to enable him to judge ; and even a reef, under such circumstances, might be slightly above the water, without his being able to see it. The Nicol's eye-piece extinguishes all this reflected light, and gives him a clear view of what is before him. To hunters and anglers this property of the eye-piece is often very valuable.

For true splendor and variety the phenomena of polarized light surpass all others in the whole range of science. Without enumerating all the advantages resulting from the discovery of Malus, we think we have answered Cui bono? on this subject to his satisfaction. -Selected.

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