Science Siftings

New Zealand Tablet, 4 January 1912, Page 54

Science Sif tings

By Volt.' -^

Fishing Aided by the Telephone. A - In any other land than that from which the sun refuses to retire at midnight /accounts\ of boatloads of ~\ men listening to the private conversations of fishes under v water would smack too much ~of the adventures of ■ Alice in Wonderland, to be taken seriously. Nevertheless the fishermen along the Norwegian coasts are just - such eavesdroppers. Every fishing vessel is now equipped with a telephone to which is attached a microphone designed to augment submarine sounds. These sounds, collected by an electrical apparatus, communicate by means of a copper wire with the receiver of the telephone installed on the boat.. By listening in the ordin- ._ ary way, receiver at ear, the fisherman can tell pre- x? cisely the moment when the. fish begin to collect. It .. is said that there is a considerable difference in the ; sounds made by the various fish as they congregate. The cod utters a guttural grunt, and the herring has a whistling intonation which is said to be ; rather musical. Plants Suffer From Fever. Not only animals, but plants may suffer and die of fevers, is the conclusion" reached by the French savant D'u Sablon. When a human being has a fever he loses flesh on account of the increased combustion, the quantity of carbonic acid respired from the lungs being augmented from 79 to 100 per cent. A plant attacked by a fever, which may be caused by a wound, > rapidly consumes its reserves of organic matter and becomes enfeebled, sometimes sufficiently to cause.its death. Du Sablon has experimented with potatoes rendered feverish by cutting them. The temperature soon rises about one degree, and the. quantity of carbonic acid given off increases several hundred per cent. If the potato survives, its 'respiration ' after a- few days becomes normal, but (says an American contemporary), it falls into an enfeebled state, resembling that of a person convalescent from a'; long fever. The Migration of Birds. The fascinating problem of ' The Migration of Birds' is discussed in the October Windsor Magazine, with many interesting illustrations. Writing of the perils that beset these ( strange journeyings, the author says:— 'Many, too, are the perils that beset the journey, for falcons and hawks of various kinds are ever ready to take toll of the wanderers, whilst lighthouses frequently prove a fatal fascination. The attraction of the lighthouse or lightship is greatest on dark, cloudy nights, when the birds evidently lose their bearings, and make for the light as being the' only landmark. ? The scene on such a night has been described as bewildering. Hundreds of thousands of migrants are m passing; the lamp is vignetted in a perfect sea M drifting birds. Some cling, fluttering like huge moth's, to the . lantern dozen are killed by hurling i themselves against the glass. Then, as the moon breaks through the clouds, and the migrating stream is" able to find its bearings again, the lighthouse is deserted, and their ; wild call-notes alone tell us that the birds are still passing far overhead. Thus it is more or less due to weather conditions that we actually see anything of nocturnal flights. For should a spell of fine starlight nights occur at the appointed time, few, if »any, birds will visit the lights, though their migration has' taken place ; just the same. In most cases it is the young and inexperienced birds that seem perplexed at such adverse circumstances, the old hands, who have travelled before, being, apparently, not distressed by them. This is scarcely to be wondered at, when we know that the young of many species, soon after leaving the nest, > are the first to start on the autumn journey*' 'South*4 For the youngsters,.. who have had no previous know-' ledge of the way, will set out to find Africa ' on their own/ Travelling some days in advance of their parents, these plucky fledglings journey hundreds of miles into the ., unknown, ; yet following almost , unerringly .an ancient bird-path which their ancestors have followed for ages.'- '