Science Siftings

New Zealand Tablet, Volume 08, 8 October 1908, Page 35

Science Siftings

BY 'VOLT

The First -Matches.The first sulphur matches, now upwards of a century old, appear very awkward according; to our modern ideas convenience. They were known as * spunks • and varied in length from five to seven inches. These were generally packed in bundles of a' doren tied together with bits of straw. Some that were made in 1830 are now preserved in York- Museum. , They were even less satisfactory than they appear, since the sulphur refused to strike fire. Boiling-point of Water. • Water boils at different temperatures, according to the elevation above the sea-level. In "London water boils practically at t, 212 degrees Fahrenheit; in Munich, Germany, at 2oa£ degrees; in the City of Mexico, at 200 degrees, and in the Himalayas, at an elevation of -18,000 feet above the level of the sea, at 180 degrees. These differences are caused by flic varying pressure of the atmosphere at" these points.- "In -Ldßßi^tKe 'whole weight of the air has to be overcome. In. Mexico^ 7000 feet above the sea, there is .7000 feet less of "atmosphere" to be resisted; consequently- less heat, is required, and boiling takes place at a .? lower, temperature. -' " . ." ' - " ; V "' • -Windmill Churn. Butter is made in a variety of "ways, by hand power, steam pbwer, even dog power; but if Is safe to say that churn herewith described is entirely a labor-saving device. The laborious old hand" churn has" been replaced among many enterprising farmers by a patent churn run by a dog treadmill. In the great- modern dairies the butter, is churned by the ton by steam or electricity. The windmill churn, in actual use in some parts of Holland, is at once a very simple and an inexpensive solution of the problem. The milk is placed in a jar or similar vessel, which is enclosed in a box, which in turn- is fixed to the axle of the windmill. The wind, of course, does the churning, and the faster the wind blows the quicker will the butter appear! Queer Positions of Hearts. ' -. There is one curious fact which not everybody notices about the common, finger-long, green caterpillars of our larger moths. Their hearts, instead of being, in front, are at the back of the body and extend, along the entire length of the animal. One can see the" heart distinctly through the thin skin, and can watch its slow beat, which starts at the tail. and- moves forward to the head. Hearts of this .sort, reaching from head to tail, are not at all uncommon in the simpler creatures.' ' The earth worm has one, and so have most worms, caterpillars, and other crawling things. .Hearts in the' middle of the back also are quite as frequent as those in what seems to us to be" the natural places Many animals, the lobster, for example, and the crayfish and the crab, - which have short hearts like those -of the beasts and} birds, nevertheless- have them placed just under the shell. in,\vh-a.t, in ourselves, would be the small of the back. ;. - The Atlantic Cable. Wednesday, August.s, marked the golden jubilee of the completion of the Atlantic cable. On August 5, 1858, after many disheartening failures, the European end . of the cable was -landed at Pouglas .Bay, Valentia, and almost immediately a message was received through it announcing that the American end -was .being landed at Trinity Bay, Newfoundland. Then followed a cablegram from Queen Victoria to the American President, and telegraphic communication between the two continents was' an accomplished fact. - True, the first cable ' was unsatisfactory, arid after a couple of months it gave out altogether, chiefly owing to the excessive current sent^through it; but the fact remained that a cable had been .successfully-laid,-and thereafter it was only a question of the improvement of the working apparatus. Then it was that the .Belfast man, Professor William Thomson, afterwards to be known "as Lord Kelvin,., came", to the rescue with his -mirror galvanometer, and the permanence of the system was assured. Since, then another scientist of Irish blood, Signor Marconi, has taught us to do' without cables altogether, but "even ., this . cannot diminish ..the greatness of the achievement of the men of fifty years ago.' ' '