Scientific.

Waikato Times, Volume XXVIII, Issue 2298, 2 April 1887, Page 2 (Supplement)

Scientific.

The Pttrity ok Air.—The purity of Alpine air has been demonstrated by Professor Tyndall and others, and a similar claim has been made for the air of the mid-Atlantic. Lecturing recently on the action of micro-organisms on surgical wounds, Professor F. S. Dennis, of New York, stated that during his last trip across the Atlantic he made some experiments to test the purity of the air about 1,000 miles from land. He employed capsules of sterilised gelatine, and exposed them for fifteen minutes. One capsule was exposed in the state-room upon the main deck of the steamer. Within eighteen hours over 500 points of infection had developed. Two capsules exposed in a similar manner in a cabin on the promenade deck, where, the circulation of air was free, showed five or six points of infection each ten days afterwards. A capsule exposed over the bow of the ship was found to be entirely uncontaminated.—Public Opinion. Thunderstorms.— From a study of thirty-two years observations of thunderstorms in the Vienna region. Dr. Hanu finds that there is a double maximum of frequency. Tho greatest number occur in the first half of June, the second smaller maximum is in the end of July ; between these is a secondary minimum (Thunderstorms hardly ever occur in Winter.) This agrees with observations in Munich. In Brussels most thunderstorms occur in the second halves of Jnne and July. The daily period in Vienna shows a chief maximum about 3.20 p.m., and a secondary one at 1.2 a.m. The spring aud summer storms come mostly from the east and south-east, and seem to belong to Mediterranean depressions, coming up from tho Adriatic, as those of lute summer seem to be on the south or southeast border of Atlantic depressions. A Scientific Prince.—The Prince of Monaco (says the Paris correspondent of the Daily Telegraph) ha a bseii occupying his spare time in a very useful and scientific manner. He has been studying the speed of ocean currents by means of a series of experiments made from the deck of his yacht, the Hirondelle. Before the close of the summer he submerged 500 bottles off the coast of the Chanuel, in the latitude of Paris, and some of them have already been found on the coast of Portugal. Tho Prince hopes to be able, according to M. Bouquet de la Grye, of "the Paris Academy of Science, to find out, by tho time of the arrival of the bottles on the distant coasts, the minimum force of the currents, a scientific problem which has been hitherto unsolved.

Glass Railroad Slekters. —Mr Siemens has stated that a sample of his irlass sleepers, tested at the Anderston Foundry Company, Glasgow, "resisted a falling weight of cwt, falling upon a rail placed upon the sleeper set in .sand ballast, beginning at six inches and rising by succeeding increments of 6 inches up to 9 feet 6 inches—the maximum elevation to which the tast ram could be elevated—without effect until the blow had been repeated for the sixth time. Castiron sleepers are expected to withstand a similar test up to 7 feet only. The cost of glass sleepers will be considerably less than those of either cast-iron or steel, ■ while the material is practically imperishable.—Mining and Engineering Journal. J