Science Sittings

New Zealand Tablet, Volume XXXV, Issue 6, 7 February 1907, Page 35

Science Sittings

By 'Volt*

Rubber Shoes.

In 1820 a pair of" rubber shoes was seen, for the first time in. the United States. They were covered with gilding, and resembled in shape the shoes of a. Chinaman. The • rubber was in some parts of the shoes from an eighth to a quarter of an inch thick. "» A" Remarkable Journey.

Numbers of experiments have been made to test the speed and destination of corked bottles thrown in the sea in various parts, of "the world. The most remarkable example ever heard of was that in which a bottle travelled 6000 rrAles in about two years and a half ; roughly, at the rate of 6£ miles a 'day.

Naval Torpedoes.

Torpedoes for the destruction of vessels were first used in the spring, of 1861 by the Confederates in the James river. In 1865 the secretary of the navy reported that more ships had been lost 'by torpedoing than from all other causes. General Rains, chief of the Confederate torpedo service, put the number at 58, a greater number than has been destroyed in all the wars since.

Summer Ice,

The peasants of Pongibaud, in the mountains of Auvergne, are acquainted with a singular summer formation of ice, presumably due to evaporation of underground moisture and consequent fall in temperature. Of this phenomenon they have for many years 'taken advantage to cool and harden their cheeses, which are deposited in certain caverns where this ice is found to Tdc present, and thus keep good during the hottest summer months.

Deep Sea Measuring

Great Britain and America do more deep sea measuring than all the other nations put together. More than one-half of the sea floor lies at a depth of a little less than *' three, miles. Some of the deepest places are holes in the ocean tied. One of these in the south Atlantic coveis 7,000,000 square miles, or 7 per cent, of the surface of the globe. The Indian ocean is a great place far deep waters, twenty-four out of the known forty-two holes lying at the bottom of that body of water.

Silver Mines.

The process by which nature forms her silver mines is very interesting. It must be rememibered that the earth's crust is full of water, which percolates everywhere through the rocks, making solutions of elements obtained from them. These solutions take up small particles of precious metal which they find here and there.. Sometimes the solutions in question are hot, the water having got so far . down as to be set boiling by the internal heat of the globe. Then they rush upward, piclAng up the bits of metal as they- go. Naturally heat assists the performance of this operation. Now and then the streams thus formed, 'perpetually flowing hither and thither below the ground, pass through cracks or cavities in the rocks, where they deposit their lodes of silver.

History of the Potato.

The common potato was, at the time of the discovery of America, in cultivation from Chili, to'which it is indigenous, along the greater part of the Andes, as far! north as to New Granada. It was introduced from Quito into Spain about 1580 under the name of 'papa,' which, in * Spanish, it still bears. From Spain it found its way to Italy, where it became known as, ' tartuflalo,'' and thence was carried to Mons in Belgium by one of the attendants of the Pope's leg^ ate to that country. In 1588 it was sent by Philippe do Sivry, Governor of Mons, to the botanisit de l'Echise, professor at the University of Leyiden, who, in 1601, published the first good description of it, under the name of 'Papas Peruanorum,' and stated that it had then spread throughout Germany. Recommended in France by Caspar Bauhin, the culture of the tuber rapidly extended--- in 1592 throughout Franche Comte, the Vosges, and Burgundy ; but the belief becoming prevalent that it caused leprosy and fever, it underwent an ordeal' of persecution from which it did not recover until three-quarters- of a century afterwards. ■ , %