Page:Popular Science Monthly Volume 13.djvu/781

Rh for those very laws by which we find the course of Nature to be determined. Take the law of hereditary descent: how did such a law, or rather, how did such a process, first commence? If this is not as legitimate a subject for inquiry as the question how came the hand, the eye, or the first germ, into existence, it is only because it seems more difficult to investigate. When the doctrine of the universality of natural law is carried so far as to include the genesis of living beings and the adaptations to external circumstances which we see in their organs and their structure, it is often pronounced to be atheistic. Whether this judgment is or is not correct, Prof. Newcomb would not undertake to decide, but said that it is very easy to propound the test question by which its correctness is to be determined: "Is the general doctrine of causes acting in apparently blind obedience to invariable law in itself atheistic?" If it is, then the whole progress of our knowledge of Nature has been in this direction, for it has consisted in reducing the operations of Nature to such blind obedience. If the doctrine is not atheistic, then there is nothing atheistic in any phase of the theory of evolution, for this consists solely in accounting for certain processes by natural laws.

A New Calculating-Machine.—Mention is made, in the presidential address of Mr. Spottiswoode to the British Association, of a calculating-machine, devised by Prof. James Thomson, which for simplicity of construction compares favorably even with Edison's phonograph. The description given of this ingenious instrument is extremely meagre and insufficient, and does not give any notion of its modus operandi. "By means of the mere friction of a disk, a cylinder, and a ball," says Mr. Spottiswoode, "this machine is capable of effecting a variety of complicated calculations which occur in the highest application of mathematics to physical problems. By its aid it seems that an unskilled laborer may, in a given time, perform the work of ten skilled arithmeticians." It is applicable to the calculation of all sorts of periodic phenomena—as those of the tides, and of magnetic and meteorological variations. It will solve differential equations of the second, and perhaps even of higher orders. And through the same invention the problem of finding the free motions of any number of mutually-attracting particles, unrestricted by any of the approximate suppositions required in the treatment of the lunar and planetary theories, is reduced to the simple process of turning a crank.

Grass and Straw as Domestic Fuel.—The Mennonites, who, for a few years past, have been immigrating to our Western and Northwestern States and Territories from the Russian Empire, have introduced into their new homes the "grass-burner stove," by means of which their houses are warmed in winter, and all their cooking done throughout the year. The grass-burner is destined to be generally adopted by settlers in regions destitute of coal or timber, since by its use straw and dried prairie-grass are made to serve as perfectly satisfactory fuel. A description of this peculiar stove, with illustrations, is given by Prof. J. D. Butler, in the Gardeners Monthly, from which we copy the following notes on its construction and performance: The material is unimportant; some use brick, others stone, while still others prefer a mixture of sand and clay. The size is considerable, not unfrequently five feet in length, six in height, and two and one-half in width. The stove is erected as centrally as may be in a dwelling, so as to heat all the rooms as far as possible. The structure may be said to have six stories, viz., first, the ash-box; second, fire-box; third, cooking-oven; fourth, smoke-passage; fifth, hot-air chamber; sixth, smoke-passage to chimney or to a drum in an upper room. The fuel box is about four feet long, and in width and height a foot and one-half. The grass or straw is thrust in with a fork. The author says that, in the house of Bishop Peters, the grass or straw is pitched into the fire-box of the stove for about twenty minutes twice or at most three times in twenty-four hours; that amount of firing-up suffices amply for cooking and heating in the climate of Nebraska. It now remains for American ingenuity to improve on this Russian contrivance—to make it simpler, smaller, cheaper, of better materials, of more elegant design, and of more economical combustion.