Science Siftings

New Zealand Tablet, 17 November 1910, Page 1903

Science Siftings

BY ‘VOLT’

Transportation of Living Fish.

Transportation of living fish from one distant country to another has hitherto failed of success. A new process is now under trial between America and Germany, and the results are being watched with keen interest by scientists on both sides of the Atlantic. The specimens are placed in glass jars, filled in the usual laboratory fashion, with a sufficient amount of pure oxygen for the voyage, and hermetically sealed. Success with small shipments on voyages of from two to three days have been recorded.

How Bells are Tuned.

"When certain bells in a chime produce discord they can be tuned. The tone of a bell may be raised or lowered by cutting off a little metal in the proper places. To lower the tone the bell-tuner puts the bell in his lathe and reams it out from the point where the swell begins, nearly down to the rim. As the work proceeds he frequently tests the note with a tuning-fork, and the moment the right tone is reached he stops the reaming. To raise the tone, on the contrary, he shaves off the lower edge of the bell, gradually lessening or' flattening the bevel, in order to shorten the bell, for of two bells of equal diameter and thickness the shorter will give the higher note. Magnets in Flour Mills.

Explosions are often caused in flour mills and breweries by nails or other iron particles that find their way in the grain and which when they strike the steel rolls of the mills produce sparks and ignite the finely pulverised material about them. Recently a large malting concern that has been troubled by many such explosions installed a set of electro-magnets over which the grain is passed before being prepared for shipment to the breweries. All iron particles in the grain are picked up by the magnets and 800 or 1000 bushels of grain are cleaned an hour. When the magnets have collected a large amount of metal they are swung to one side, de-energised and swept clean of any particles adhering to them by residual magnetism. Since the installation of these magnets there have been no explosions in the mills. Paris to Speak to New York,

In a very short time (says the London Daily Mail) it may be possible for a man standing at the Eiffel Tower in Paris to speak across the Atlantic to a person in the Mutual Life Office (the highest inhabited building) at New York, over 3500 miles away. The necessary installations will, it is stated, be then completed. Should the experiment prove as successful as anticipated, people will bo able to speak across the Atlantic between these two cities without even raising their voices. The system of telephony adopted for these experiments by the French Government is that of De Forest, an American inventor, which was tried last summer between the. Admiralty Offices at Whitehall and certain ships stationed in the Channel. Previously to this the Admiralty, at Portsmouth, had been in communication with ships in the Channel fitted with De Forest's apparatus, and had been convinced that in the case of a naval battle in the Channel the commander of a vessel directing his ship could talk with the Admiralty from the bridge. Ultra-Violet Rays. That the violet, and the ultra-violet, rays of the spectrum possess germicidal properties was demonstrated as far back as the eighties by Englemann. By means of a microspectral objective of his own invention he focussed a pencil of rays of every color of the spectrum, on a preparation of bacteria, to find that the bacteria which up to that time had been distributed haphazard through the preparation deserted the violet end, to crowd themselves in the red and infrared of the spectrum. The explanations of this preference have been various. The most recent theory, however, is that of Kernbaum, who claims that the ultra-violet rays, chemical in constitution, when acting on water forms hydrogen peroxide, a powerful antiseptic agent. His observations have been corroborated by Thiele and Schoene.

Size and Work of the Heart.

It has been found recently that the relative size of the heart in different groups of animals depends on the amount of work it is called upon to perform. This is announced by Miss F. Buchanan, writing in Science Progress on the significance of the pulse-rate in vertebrates. Says nature in a brief abstract; —‘Thus in fishes, where it has only to pump the blood so far as the gills, the heart is always small, averaging 0.09 per cent, of the body-weight; but in the inert flat-fishes it is still smaller, being only about 0.04 per cent, of the body-weight. On the other hand, in birds, more especially migratory and vocal species, the heart has very heavy work to perform, and is consequently of great relative size, ranging from 1 to 2, or in a few cases 2.6 per cent, of the body-weight. In consequence of these differences in the amount of work the heart has to execute, its size bears no fixed relation to that of the animal to which it belongs. The heart of a pigeon, e.g., weighs 25 times that of a plaice of the same weight, and is about equal to that of a salmon 15 times as heavy as the pigeon. A thrush, and a guinea-pig of six or seven times its weight, have hearts of about equal size.’