Page:Popular Science Monthly Volume 19.djvu/153

Rh they are liable to be interfered with by unfavorable atmospheric conditions, so as to greatly reduce their radii of visibility. With electric lights having the powers that M. Allard proposes to apply, the period during which the penetrative power may be deficient will be reduced to sixty days, or one sixth of the year on the ocean, and to twenty-four nights, or one fifth, on the Mediterranean coast. The cost of the proposed changes is estimated at seven million francs, or eight million francs if sound-signals are also provided. It is believed that the cost of keeping up the light after the change is made will be several times less than that of maintaining the oil-lamps.

 

bureau has been established, in connection with the Winchester Observatory of Yale College, for the more accurate graduation and verification of thermometers. The thermometers in common use are, as a rule, not graduated with any approach to scientific accuracy, and the best of them, however exact they may be when new, increase their readings rapidly within a few months, so as to become as much as 2° in error in the course of a year. This is a matter of particular importance with clinical thermometers, of which several thousand are bought every year; and to instruments of this class special attention is paid.

late Mr. Frank Buckland has bequeathed his valuable museum of "Economic Fish Culture" to the British nation, with the sum of £5,000 to go to the nation on the death of Mrs. Buckland, to be applied to the foundation of a professorship of economic pisciculture in connection with the Buckland Museum and the Science and Art Department at South Kensington.

to employ artificial lights for the capture and destruction of noxious insects has found considerable favor. A medal was awarded at the last exhibition of agriculture and insectology in Paris for a lamp especially adapted for catching insects. The electric light has been found to be a very effective insect-trap, and its eventual coming into use for this purpose in bug-infected gardens and orchards may be regarded as among the things that are possible.

is the name which Dr. Comte, a French army-surgeon, has given to a novel application of tattooing as a help in the saving of lives. Believing that a large proportion of deaths by bleeding from wounds received in battle might be avoided if the men knew just where to apply compression to the arteries till the surgeon should come, Dr. Comte has marked the most suitable points for the application by tattooed designs on the skins of the men of his regiment.

of Philadelphia, has observed that the Yucca gloriosa has the property of collecting moisture on the outer surface of its flowers to such an extent that drops will fall to the ground. In the plant in which this peculiarity was first noticed, the whole outside of the flowers was covered with moisture; it accumulated in drops at the tip of each leaf of the perianth, and the under leaves showed by their appearance that a dropping of water had been going on for some time. Mr. Meehan could not decide whether the liquid was an exudation from the leaves, or had been condensed from the atmosphere through some special property of the plant, like that which is attributed to the rain-tree (Pithecelobium saman) of Peru.

one of the commanders of the Austro-Hungarian Polar Expedition in the Tegetthoff, which discovered Franz-Josef Land in 1874, died in Vienna, March 29th.

and A. Michel Lévy have produced an artificial basalt identical in all respects with the natural basalts, and particularly so with that of the plateaux of Auvergne. The experiment is regarded as establishing the igneous origin of the basalts.

has called attention in the "Journal de Pharmacie" to woolen mattresses as a possibly fertile nidus for disease. In a large city such mattresses may represent millions of fleeces that have been only partly cleared of grease, and have, moreover, been affected by long use through successive generations. They are rarely efficiently purified, and might become an active medium for the propagation of infection.

an eminent naturalist, died at Santa Cruz de Teneriffe in November last, in the eighty-seventh year of his age. He had made the Canary Islands his home for sixty years, and had done much to increase the knowledge of their natural history. His principal work was the preparation, in conjunction with Mr. Philip Barker Webb, of a series of six quarto illustrated volumes on that subject ("Natural History of the Canary Islands"), which was published in 1828. He was consul of France, and a member of the principal scientific societies of the Canaries and of Europe. 