Page:Popular Science Monthly Volume 24.djvu/297

Rh Liverpool and other ports at which diseased animals were landed became centers of contagion. The history of this disease is only one example out of many in the list of maladies to which animals are liable. The study of Mr. Fleming's histories induces the conviction that hardly a creature in any way connected with man, or coming under our observation, is free from liability to hosts of plagues, or has not its full share of special or common troubles. Mr. Fleming's work is published in England.

Wind-Sounds in the Desert.—The travelers' tales of sounds like the ringing of bells, which they have heard in deserts and lonely places, are familiar. Some of them are too well substantiated to admit of serious dispute. Among them is that of the noises heard at the Gebel Nakus, in the Sinaitic Peninsula, which the Arabs say proceed from a convent of damned monks; the musical cliffs of the Orinoco, told of by Humboldt; and the sounds which the French savants Jollois and Devilliérs declare they heard at sunrise at Karnak, Egypt, and described as comparable to the ancient fable of the vocal Memnon. The sounds are not always or exactly like the ringing of a bell; sometimes they resemble the music of a string, and may be generally described as of an intermediate character between the two classes. A characteristic of the sounds is, that no one can discern where they come from. M. Émile Sorel, fils, in order to determine their origin, has made some successful experiments in reproducing them artificially. Taking his gun into an open field, he placed it at an angle of 45° against the wind, when it gave forth a sound. Then moving it around, he caused it to utter the exact tone he sought. The sound could not be localized. Addressing a peasant, he asked him, "Do you hear my gun? "Pardon, monsieur, it is the bells of ." A similar answer was got from every one whose attention was called to the noise. It was believed to come from about two miles and a half to the windward. M. Sorel believes this experiment authorizes the hypothesis that the ringing is the result of the blowing of the wind over a slope at the foot of which is something that may act as a resonator. What is done on a small scale in a gun may be done on a large scale in nature, on the face of a mountain or a rock which is backed by a valley or a ravine, or which is itself elastic enough to give the resonant effect. The sounds are apparently not as readily given when the vibrating surfaces and media are moist.

Artificial Drying of Fodders.—A practical, economical apparatus for artificially drying fodder-crops might be the means of effecting immense savings to farmers in bad seasons for hay-making. Mr. William A. Gibbs has described before the British Society of Arts two such apparatuses which, he claims, accomplish the object at a cost that makes their use profitable. His own apparatus, which he has spent many years in perfecting, is in its primitive and simplest form a stove or furnace for burning coke, to which is attached a fan for blowing the hot air resulting from the combustion—of a temperature that may rise to 520°—through the wet grass. An exposure of from four to six minutes is sufficient to convert each lot of grass the proportion of which is adapted to the force of the blast into hay. This has been developed into a machine of eleven tons weight "which, when in action, eats up a one-horse load of coke, draws off ten to fifteen tons of water, and converts twenty great cart-loads of wet rubbish into good stack-hay in a single day's work." The perfected machine has a system of giant forks and flat iron plates, kept in rapid action, through which the wet grass is shaken down in successive stages while it is permeated through and through with the hot air. Another process, the invention of Mr. Neilson, is for cooling hay in the stack, and uses the heat which is developed in the natural process of "heating," to dry the whole. A hole six inches in diameter is bored through the stack to the point at which the greatest heat is developed, and a fan fixed at the outlet of the hole is made to draw off the heat from that point and promote the ventilation and drying of the whole mass. Mr. Gibbs believes that these processes are about equal in value, and that their value is real. He also described a "sheaf-tube" for drying sheaves of wheat. It is "like a gun-barrel open at both ends, and about eighteen inches long; such tubes