Imágenes de páginas


believing that at the depth of a few miles the earth becomes a molten mass of matter. But between this molten mass and the surface, and generally not far below the surface, there is some point where the temperature is constantly that of the mean temperature of the place. The air of caverns and springs is generally of this same mean temperature; though there are many warm springs which seem to be formed of condensed vapor that is thrown up to the surface through cavernous passages from the heated core of the earth. As a general rule, spring water retains nearly the same equable temperature the year through, and hence, in the temperate regions it appears to be warm in the winter and cold in the summer, in the same way that moral moderation will always seem extreme to extremists.

On ascending into the atmosphere the thermometer talls ; and it has been usual to allow one degree for every hundred yards. Recent observations however, made during balloon ascensions, go to show that this estimate cannot be relied on with certainty, there being at times warm upper currents in the atmusphere the temperature of which may possibly be warmer than the air at the surface of the earth. Yet that the temperatnre of the air does decrease as we ascend into it, is made strikingly evident to one who climbs to elevated mountain summits, and especially within the tropics. During an ascent of less than three miles, one there passes from all the glow and heat of the tropics, through every gradation of temperature and climate, up to the desolation of the polar regions. From the mountain tops upwards the air grows colder as it becomes more thin, until finally the stellar spaces are reached, where there is no air, and probably there the temperature is far below zero.

There are upon the earth other sources of heat besides those of the sun. Of these, chemical combination is the most prolific. It is from this source that animal heat is derived; and which is generally greater than that of the : place where it is evolved, as may be seen by putting the bulb of a small thermometer in the mouth. This heat is derived in a great measure from chemical action upon the food which is taken into the system, which may be regarded as a fuel, more of it being needed in a cold climate than in a warm one. The resident of the arctic re. gions may consume as much as ten pounds of meat a day without injury, while if one in the tropics should eat but one pound a day it might throw him into a fever. And probably, not a few of our own fevers in Vermont are occasioned by habits of over eating incurred during our long cold winters; the custom of eating pork, one of doubtful propriety at any time, extending with many throughout our intensely hot summers.

Beşides animal life, it would be a curious inquiry to examine whether vegetable life also, is not endued with some power to produce its own temperature; to keep .itself warmer than the air in winter, and cooler in summer. Yet doubtless many of our readers have been in the woods in the depths of winter, when the thermometer was atits. lowest range of the year, and heard the trees snap as if shrinking under the intense cold.

The mean annual temperature of a place is ascertained by taking a mean of three observations a day of the thermometer. throughout the year; the sum of the daily observations being divided by three, the sum of the daily means being divided by the number of days in the month and the sum of the monthly means divided by twelve. The observations are carefully and punctually made at the hours of 7 a. m., 2 p. m., and 9 p. m., each day. The tbermometer should be placed in the open air, on the North West side of the house, and be carefully guard, ed against the direct rays of the sun, against reflection from a white wall or other surface, and against all heat from the interior of the house. Any errors from these. · sources would render the results defective and unreliable.

[blocks in formation]

None but the best of instruments should be used, such as are recommended by the Smithsonian Iustitution.

Those who reside near rivers, streams, lakes or ponds. fvould find it interesting to keep a record of the temperature of these bodies of water throughout the year, with a careful observation of the circumstances attending the rise of fogs from their surface. The temperature of forests as compared with that of the open country would also be. Interesting

Some few facts disclosed by the thermometer may be stated as follows. The mean temperatures of the months of April and October are very nearly the same as that of the year.

The greatest degree of cold in the Northern hemisphere. occurs about the middle of January; and the thaw that usually takes place in that month seems to be occasioned by a rush of warm vapors from the Equator stimulated by the contraction of the atmosphere from a great degree of cold, a partial vacuum being created, as it were, by the eontraction.

A sudden cold spell is sure to occur somewhere about the middle of September, and generally after the preva. lence of several days of very warm weather; as no provision of warm clothing is made to meet this sudden change it generally occasions much sickness.

We write this article on the 22d day of September, or the first day of Autumn, during a cold spell that commenced on the 19th, after several very warm days. As we have had a great deal of rainy south east winds during the past summer, which have been as constant, almost as those winds usually are on the coast of South Carolina, we shall undoubtedly have a prevalence this fall and winte of return winds from the North. And as, after so much rain, the air will probably be dry, which is generally a cold air, we may. look for an unusually windy and cold fall and winter.

J. W. P.

[blocks in formation]

Be earnest, teacher; as the hours Ait by,

Let each a goodly record for you bear,
Remember, what you do will never die,

For souls immortal must your impress wear.

Be earnest, teacher: for those burning thoughts,

Those “buds of song” your soil cannot unfold, Nurtured in the young hearts that you have taught,

They yet may blossom to a grateful world.

Be earnest, teacher; for those waiting minds,

Shrivelled or full, shall still your ļikeness bear; . And whose will be the fault if future finds

A frightful image deeply mirrored there?

Be earnest, teacher; count your calling high.

Authors seek power o'er souls through printed lines; You reach the heart through both the ear and eye,

And thus direct, impress those youthful minds.

Be earnest, teacher; hear the future call;

It urges you to guide those souls aright,
Bids you remember, in them resteth all

Its hopes of truth, of liberty and light.

If you unfaithful prove to your high trust,

No crown against your name will be enrolled,
And you shall sleep in death's dishonored dust,
And meet beyond, the taunts of injured souls.

L. A, K.

Pride, like an eagle, builds among the stars ;
But pleasure, lark like, nests upon the ground.

Thoughts shut up want air,
And spoil, like bales unopened to the sun.,

Expense of our Public Schools.




According to Secretary Adams' last Report the total expenditure for Schools during the preceding School year was $375,976.

In view of the statistics, here presented, Mr. Adams makes the following appropriate and forcible remarks:

"It is difficult to see how in the minds of any portion of our people, a public interest which, apart from all its other manifold and peculiar claims to attention, annually involves so great an expenditure, can be allowed to take any other than the highest rank, as a subject of thought, discussion, or legislation. And it seems passing strange that while all receive and assent to the proposition that whatever involves an expenditure of the public money, therefore deserves and should receive a proportionally rigid scrutiny and supervision; any should be found will. ing to allow the administration of the public school sys. tem to be carried on without a constant and efficient ex. amination and exposition. For many years the attention of the public mind hes been solicited so exclusively to the moral and social bearings of the successful use of the means and instrumentalities for general culture, that the financial importance of the school system, as in its admin. istration necessarily and constantly involving the expen.. diture of a vast sum of money in each year, has been nec. essarily lost sight of. From this is has resulted that keen and sagacious business men have been to a great extent averse to intermeddle in the direction or management of educa. tional matters.; having, in the preponderance given to their moral and social claims, failed to retain a due appreciation of their practical importance as requiring an enormous pecuniary expenditure.

For these reasons therefore, the annual presentation of the pecuniary importance of the schools as measured by thue necessary expenditure of money involved in their sup: port, is desirable. So long as from this annual ex position it authentically appears, thạt the State, in time of peace

« AnteriorContinuar »