صور الصفحة
PDF
النشر الإلكتروني

claim in the annual interest on his investment in preparation, in the shape of a diminution and loss of wages for two years of apprenticeship, say $200 a year, or $400 in all, the interest on which we may call $28 a year-he being rated then as a mere laborer, but supported by his parents, and that support reckoned in casting their wages. The above makes his total annual claim for wages $1,038, which, divided by 200, the only amount of days in a year that a bricklayer can work, gives $5 a day, or 62 cents an hour.

And now we will close, though we might go on, by taking other occupations, say that of the sewing girls. There we should find that, in the practice of the admirable union houses that are in operation for them in New York, the present actual expense of their board has been from $2.75 to $3.25. This, of course, makes no allowance for the fair wages of private housekeepers who may take them to board. As a general thing, whatever is taken from the usual boarding-house price of board of a class, is subtracted from its sufficiency, wholesomeness, and cleanliness, and therefore cannot determine proper, fair, and just wages.

We might take carpenters, a class which the customs of society require to have more expensive boarding arrangements and larger personal expenses, and who must claim annual interest on their investment of capital in extended and more expensive apprenticeship and more highly-educated labor, and for the additional item of interest on capital invested in tools, and workplaces, and conveniences, and motive power, and the labor of others in transportation, &c., and the longer time he lives, and the fuller number of years, and of days in a year, that he can work.

And finally, we might sketch the wages of a professional man; a lawyer, for instance. The higher board he must pay, the larger social expenses his position imposes upon him, the great investment of capital and time in his academie, collegiate, and professional studies, and their bonus; the expense of his furnished offices and attendance, his costly library, his employment of other labor-clerk, copyist, and junior partner-his stationery and travel, all items of claim for his wages. And further than that, the impossibility of limiting

[ocr errors]

his thought, study, and toil to the set eight daily hours of labor.

But we trust we have sufficiently and plainly enough set out and provided a practical measure of the claims of wages of labor, in the different classes of human occupation.

ART. VII.-1. A Popular Treatise on Comets. By JAMES C. WATSON, A.M. Philadelphia, 1861.

2. A Treatise on Comets. By J. R. HIND. London. 3. Exposition du Système du Monde.

LAPLACE.

Mécanique céleste.

4. Histoire de l'Astronomie au dix-huitième siècle.

Mathieu.

5. Histoire de l'Astronomie ancienne et moderne. BAILLY.

THERE is no science, perhaps, which is at present making more rapid progress than that of astronomy. This advancement is not marked so much by grand and startling discoveries as by the correction and the perfecting of old and established theories. This labor is not to be performed by minds. of moderate power, but the master minds of the age devote their time to it. Old theories and calculations are reëxamined with a minuteness which nothing but a deep interest in the subject could inspire. It is not alone in physical astronomy that progress is made; the spectroscope is revolutionizing many of our ideas in relation to the physical constitution of the celestial bodies. Well-equipped astronomical observatories are now to be found in nearly every part of the world where civilization has gained a foothold; not only in Europe and North America, but also in South America, Asia, Africa, and Australia. Many individuals of wealth in this country and in Europe have established private observatories, which are either under the direction of their owners or of persons competent to take charge of them. With this multiplicity of observers scarcely a new celestial phenomenon can pass unnoticed. Formerly the principal authorities in astronomy were the Herschels, but now we have them by the score.

Cometary astronomy receives especial attention. Scarcely.

a comet makes its appearance in the heavens without being detected by one or more of the numerous observers, long before it reaches its nearest point to the earth, and when it is visible with the comet-seeker only as a faint nebulous object. The labour expended in discovering a comet in a regular search for one, instituted for the purpose, is really immense. It requires several year's preparation before a person is fitted for such an undertaking. "The astronomer with

his telescope, begins at the going down of the sun, and examines in zones, with the utmost care and vigilance, the starry vault, and continues till the circling hours' bring the sun to the eastern horizon, when star and comet fade from his view. It requires several nights to complete a thorough survey of the heavens, and often these nights do not follow each other in succession, but are interrupted by the full moon, by clouds, auroras, and by various other meteorological phenomena. He is frequently vexed by passing clouds, fleeting through the midnight sky, and by strong and chilly breezes of the night. His labours are continued throughout the year, and his unwearied exertions do not slacken during the long wintry nights, when the frozen particles of snow and ice, driven before the northern blast, cause the stars to sparkle with unusual lustre, and his breath to congeal on the eyepiece of the telescope. It frequently happens that his labours are not crowned by a discovery, until after several years' search."

Anciently, comets were generally regarded as meteors engendered in our atmosphere. Some supposed them to be prodigies indicating wars, pestilences, famines, inundations, and earthquakes. Others, however, considered them planetary bodies, or wandering stars. According to Aristotle, Anaxagoras and Democritus supposed comets to be produced by the conjunction of many planets or stars. Zeno, the Stoic, entertained a similar view of comets. Being contested in this view by contemporary philosophers, who stated that the number of planets was not sufficiently great to form all the comets which had appeared, it was replied that the number of planets was unknown; that by far the greater number moved in orbits so elongated, that they only return

ed after intervals of great length; and it was only in that part of their orbits which lies nearest the earth and sun, that they could become visible. The Pythagoreans, who approximated nearest to the true system of the world of any of the ancients, regarded comets as planets, which return only after long intervals, and approach as near the sun as Mercury. The views entertained in that age were much more nearly correct than those held a thousand years later. Olympiodorus, a peripatetic philosopher in the age of Theodosius the younger, maintained that a comet is composed of dry vapors in our atmosphere, and set on fire by the heat of the solar rays, and afterwards extinguished by the moist vapors of the earth. Aristotle supposed comets to be enkindled in our atmosphere, to burn for a greater or less period of time de pending on the length of their period of visibility, when they became extinguished. No philosopher of antiquity exercised a greater influence on the philosophy of the Middle Ages than Aristotle, and it is to be regretted that the views which he entertained of the nature, magnitude, and structure of the universe, were not of a higher order, and more in accordance with nature herself. He describes the grand views of the Pythagoreans in the same book in which he sets forth his

own.

We must not omit to give the views of Seneca on comets. He seemed endowed with an intuition which in very many cases led him to correct conclusions respecting the phenomena of nature; and which made him one of the greatest philosophers and moralists of antiquity. "For I do not think, he says, that comets are a casual outburst of fire, but belong to the eternal works of nature. For why should it surprise us that comets, so rare a phenomenon, should not yet be subject to the regulation of any known laws? and that their origin and ends should be hid from us, who see them only at immense intervals? It is not yet five hundred years since Goerer gave names and number to the stars. And to this day there are many nations who know nothing of the heavenly bodies but as they appear to the eye, who are still ignorant of the canses of the waves and the eclipses of the moon; even we ourselves have only lately attained an ac

curate knowledge of these phenomena. The time will arrive when the diligence of a remoter age will throw light on subjects which are now involved in obscurity. The time will arrive when our posterity will wonder at our ignorance, of things so plain to them. Eleusis reserves her favors for those who repeat their visits. Nature does not permit us to explore her sanctuary all at once. We believe we are initiated; whereas we halt at the very threshold. Those mysteries are not revealed indiscriminately to all; they are laid up and enshrined within the penetralia. Some are revealed to the men of our age, some to those who shall come after us. Great results proceed slowly." *

It is a thing worthy of note that the superstitious notions of the Middle Ages respecting the influence of comets on the earth, and the danger of the destruction of the human race from these celestial visitors, are not to be traced in the writings of the ancients.

The earliest recorded appearances of comets which seem to be authentic, are to be traced in the Chinese annals, as early as 613, B. c.† The Chinese have professedly recorded the appearance of comets since 2550, B. c.; but the accounts given are quite vague and unsatisfactory. Comets were also observed by the Chaldeans at a very carly date, but the record of their observations has not come down to us. The Chaldean astronomers, according to Diodorus, considered the comets as bodies subject to the same dynamic laws as the planets, but receding to a greater distance from the earth; but the Chinese were satisfied with making extended observations on them, without any attempt at an explanation of the laws which regulate their motions or govern their physical phenomena.

In the

It is to Tycho Brahe that we owe the discovery that comets are situated beyond the limits of our atmosphere, and even beyond the orbit of the moon. In the year 1577 & very fine comet made its appearance in the heavens, which was subjected in its motions to the closest scrutiny by Tycho, with his large and accurate instruments, and failing to dis

*Nat. Quæst. lib. vii. cap. xxii. xxv. & xxxi.

+ Cosmos iv., p. 539.

« السابقةمتابعة »