Page:Popular Science Monthly Volume 2.djvu/396

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images, analogous to the alternations produced by increase of distance. This remarkable fact Prof. Mayer proposes to employ in measuring temperatures, and particularly the high temperatures of furnaces. This is to be accomplished by interposing a coil of porcelain or other fire-proof pipe between the resonance-sphere and the jet, and introducing it slowly into the furnace. By this method, Prof. Mayer expects to be able to measure temperatures with an accuracy equal to about twenty-five degrees of the Centigrade thermometer, or even less.


A New Species of Rhinoceros.—A writer in Nature is disposed to see, in the hairy-eared, two-horned rhinoceros at present in the menagerie of the London Zoological Society, a new species, which he proposes to call R. casiotis, the hairy-eared rhinoceros. When this animal arrived in England, it was taken to be the Sumatran rhinoceros, though naturalists were surprised that a Sumatran rhinoceros should be taken so far north as was this specimen—Chittagong, the northern extremity of the Bay of Bengal. There is a fringe of long hairs on the posterior rim of the otherwise naked ears, and the tail is long, and tufted at the extremity. The head is very broad, and the skin comparatively smooth.


Nothing new under the Sun.—Humboldt, in his "Cosmos," states that the Chinese had magnetic carriages with which to guide themselves across the great plains of Tartary, one thousand years before our era, on the principle of the compass. The prototype of the steam-engine has been traced to the eolipyle of Hero of Alexandria. The Romans used movable types to mark their pottery, and indorse their books. Mr. Layard found in Nineveh a magnifying lens of rock-crystal, which Sir D. Brewster considers a true optical lens, and the origin of the microscope. The principle of the stereoscope, invented by Prof. Wheatstone, was known to Euclid, described by Galen fifteen hundred years ago, and more fully in 1599 a. d., in the works of Baptista Porta. The Thames Tunnel, thought such a novelty, was anticipated by that under the Euphrates at Babylon; and the ancient Egyptians had a Suez Canal. Such examples might be indefinitely multiplied, but we turn to photography. M. Jobard, in his "Nouvelles Inventions aux Expositions Universelles," 1857, says a translation from German was discovered in Russia, three hundred years old, which contains a clear explanation of photography. The old alchemists understood the properties of chloride of silver in relation to light, and its photographic action is explained by Fabricius in "De Rebus Metallicis," 1566. The daguerreotype process was anticipated by De la Roche in his "Giphantie," 1760, though it was only the statement of a dreamer.


The Sun as a Borer of Mountains.—1. The universe is filled with rays of heat and light, which vibrate among the heavenly bodies perpetually without loss or gain, and which, on alighting upon a heavenly body, pass first into common sensible heat, to be reflected afterward as cold, invisible rays.

2. Of the inexhaustible supply of these rays, our sun receives at every instant of time as much as he radiates back again.

3. A portion of his rays fall upon our earth, where they are converted into sensible heat.

4. By means of this sensible heat, water is converted into aqueous vapor; the sensible heat being at the same time changed into so-called latent heat, or chemical motion.

5. Aqueous vapor having less specific gravity than air, it ascends and represents a lifted weight. In this process, heat is converted into motion—the ascent of the weight.

6. The expansion of the air (during which heat is converted into mass-motion) causes the aqueous vapor to be spread over the surface of the earth.

7. By the condensation of the aqueous vapor, chemical motion escapes as common heat, and the resulting water is deposited on the mountain-heights in the form of snow; thus, again, representing a lifted weight.

8. The warm winds from the Mediterranean melt the snow and glacier-ice; sensible heat is thus converted again into insensible chemical motion.