Page:Popular Science Monthly Volume 4.djvu/657

Rh sulphide. The artificial carbonate of baryta, produced by passing carbonic acid through a sulphide of barium, is much used in Europe in the manufacture of achromatic glass.

Subterranean Fish.—For the purpose of supplying water to a new wharf at Point Hueneme, southeast of San Buenaventura, Cal., an artesian well was sunk not five feet from high-water mark. At the depth of 143 feet a strong flow of water was obtained, which spouted 30 feet high. A goose-neck was fitted on the bore so as to reverse the flow. One day while the agent was absent, the men noticed fish in the waste-water. On his return attention was given to the fact, and the well was found to be filled with young trout, thousands of them being thrown out at every jet. These trout were all the same size (about two inches long), and perfectly developed. They had perfect eyes. There is no stream nearer than the Santa Clara River, several miles distant. There are no trout in the lower portions of the river. The temperature of the water is the same as that of the wells of this country (64° Fahr.), too warm, of course, for trout to live long in.—American Journal of Science.

New Refrigerating Machine.—A refrigerating apparatus, invented by Captain Frederick Warren, British Navy, is described as follows: It consists of a small steam-engine, to which is attached a second cylinder for condensing ether-vapor. The cold produced by the expansion of this condensed ether is utilized by being communicated to brine contained in pipes, around which the ether circulates. The brine thus cooled is used in its turn either to freeze water or to cool air, the water being contained in reservoirs immersed in a vessel of cold brine, and the air being conveyed in pipes which wind backward and forward in the brine. The ether employed, being contained entirely in closed apparatus, is scarcely at all wasted, and little more than its first cost need be taken into account.

In the experiments made with the machine, the moisture on the outside of the pipes leading to the refrigerator was rapidly frozen, and the air of the room, after being withdrawn at a temperature of 62° Fahr., was almost immediately returned to it at 45°. As this process continued, the temperature of the room was rapidly reduced, and might easily have been brought to the freezing-point and so maintained. Captain Warren claims that the temperature of any limited space can be thus kept down to almost any required degree, and he proposes to apply the method to the construction of cold chambers on board ships, to be used for storing fresh provisions, or, in the case of merchant-ships, for the conveyance of perishable freight. He does not, however, think it possible to freeze a whole cargo of meat, so as to resist putrefaction in a long voyage, as from Australia to England. He proposes to cool railway-carriages, to provide cool vases for the conveyance of meat and other provisions in India, to cool the air admitted into hospital wards, and to provide an unlimited supply of pure ice at almost nominal cost.



latest application of the sand-blast is for cleaning the fronts of buildings, by removing the soot, dust, and other substances therefrom. The impact of the sand on the surface removes the dirt from all the crevices and indentations, without perceptibly affecting the sharpness of the architectural ornamentation.

the course of a lecture on mercury recently delivered at Vienna, the leg-bone of a man was exhibited, whose death had undoubtedly been hastened by mercury. On striking the bone heavily on the table, out fell thousands of little glittering globules, which rolled about on the black surface before the lecturer, collecting here and there into drops. This mercury had been absorbed during life, and proved the death of the absorbent.

1871 the census of Ceylon was taken, it being the first attempt of the kind in that island. When this measure was first talked of, a belief prevailed in the minds of the Cinghalese that it was but a preparation for the levying of a new tax. In many districts the natives said that the object was to discover the number of unmarried youths, with a view to their being deported to Europe, whose male population, they said, had been destroyed by a great war. This led to an unusual number of marriages being celebrated. The population of the islands is 2,500,000. Their religion is looked after by 5,345 Buddhist priests, 1,078 Sivite 