Page:Popular Science Monthly Volume 24.djvu/591

Rh boiling paraffine, which destroys their capillarity, while it does not affect their conducting power. The superficial paraffine may be scraped off after the bath. Piles may be obtained by this means that will endure indefinitely, and have, apparently, an electro-motive force superior to that of a Leclanché pile of the same dimensions.— (translated for the Popular Science Monthly from La Nature).

Lightning without Audible Thunder.—A correspondent of "Nature" reports a violent rain and lightning storm which took place near the crest of the Apennines, and during which no sound of thunder was heard. The writer also describes two other such storms that he witnessed on the edge of the Montenegrin highlands. "On these nights," he states, "the lightning was so incessant and vivid that we were able to walk about, choosing our way among the stones and shrubs as readily as by daylight, the intervals between the flashes being, I should judge, never more than a minute, while much of the time they seemed absolutely continuous, the landscape being visible in all details under a diffused violet light. Looking overhead, the movements of the lightning were easily discernible, the locality of the discharges varying from one part of the vault to another in a manner which it was impossible to confound with the reflection of lightning from a distance. Like the storm of last night, those were followed by copious rain, but not a single peal of thunder was heard during the whole night."

Combustion-Products from Different Lights.—The following figures show the amount per hour of combustion-products from several varieties of artificial light. Unless the electric light has some peculiar injurious influence, it has a great superiority on sanitary grounds:



, in a paper read before the California Academy of Sciences, announces his conclusion, from his studies of the shells of the Colorado Desert and the region farther east (particularly from studies of Physa and Anodonta), that every item bearing upon the geographical distribution of the species indicates the mountain-lakes as the sources whence they are derived; points to their descent from northerly regions as well as from higher altitudes; and contributes additional testimony as to the antiquity of these widely spread though inferior forms of life.

, of the United States Coast Survey, died in Washington, December 13th, in the seventy-seventh year of his age. He had been connected with the Coast Survey during the greater part of his life, and was at the time of his death first assistant superintendent of the service.

a paper before the American Association on the "Serpentine of Staten Island, N.Y.," Dr. T. Sterry Hunt expressed himself in favor of the opinion of Dr. Britton, of the School of Mines, Columbia College, that the belt containing the mineral is a protruding portion of the Eozoic series. The appearance of isolated hills and regions of serpentine is common in other regions, and is by Dr. Hunt explained by the consideration that this very insoluble magnesian silicate resists the atmospheric agencies which dissolve limestones and convert gneisses to clay—the removal of which rocks leaves exposed the included beds and lenticular masses of serpentine. Similar appearances are seen in many parts of Italy, where ridges and bosses of serpentine are found protruding in the midst of Eocene strata, and have hitherto, by most European geologists, been regarded as eruptive masses of Eocene age. Mather, who described the Staten Island locality more than forty years ago, also looked upon the serpentine as an eruptive rock.

instance of the kindling of a fire by means of the concentration of the sun's rays by a globular water-bottle through which they passed is related by a correspondent of "La Nature." The day was cold, but the sun shone brightly; the bottle, an "onion-shaped" flask, filled with water so as to form a perfect lens, sat upon the table. The starting of the fire, which would have caused great damage if the relater of the incident had not been present to extinguish it, was revealed by the smoke. A deliberate experiment was made on the next day, with complete success, in kindling a fire by this means. 