SCIENCE GOSSIP.

New Zealand Mail, Issue 1199, 22 February 1895, Page 9

SCIENCE GOSSIP.

AN EXCEPTION TO A RULE.

It is generally supposed that when a man's heart pulsations go down to 40 a minute, death with follow unless restoratives are administered. Parisian doctors are now, it is said, puzzled over a man in one of the hospitals, whose pulsations have sunk as low as 18 a minute, although to all appearances he is well and strong.

A NEAR HIT.

A remarkably clever determination of the angular diameter of the sun was made by the Chaldeans by the use of one of the earliest forms of time-measuring apparatus. At the moment the sun'a disc appeared in the eastern horizju a fine stream of water flowing from the bottom of a vessiel in which the ilevel was kept constant, was caught in a small cup into which it was allowed to flow until the lower limb of the sun was visible. The small cup being instantly withdrawn, another muoh larger vessel was substituted for it, and into this the small stream fell during all the day and until the sun appeared in the east again on the following morning. It was found that the water in the large vessel was 720 times tfrat In the smaller, from which it appeared that the aoparent diameter of the sun was 1 720th of the circumference of the heavens, or one half a degree of an arc —not far from the truth.—Prof. Menlenhall.

USEFUL, IF NOT PRETTY.

Frogs and toads arc very useful "reptiles" in gardens and fields; but their numbers have been so reduced in this country that the batrachians are now actually imparted, mostly from America. It is stated that a few years ago a few bull frogs were introduced to Singapore, where, despite the numbers of their natural enemies, they multiplied so rapidly as to become a nuisance, from the noise they made at night. In France and America, to say nothing of China, some species of frogs are "protected," because they afford the epicure a dish in which he delights. The toad is protected in this country in gardens, as the little damage he does is amply compensated for by his work in devouring insects, &c, and he is specially valuable in market and other garde.is where much frame culture is carried on. Of late years toads have been imported in considerable numbers. — English Mechanic.

A GREATER FORTH BRIDGE.

The Americans are bent upon beating us in bridges. The bridge across the Hudson River at New York is to be on the same plan a 3 the Forth Bridge, but is to be ** bigger" in several particulars. The minimum span will be 3200 ft., as against 1700 ft. in the Forth Bridge. This means that there will bo no pier in the river. The two steel shore piers ara to be 620 ft. high, as against the 355 ft. of the Scotch piers. The anchorages for the suspension chains will be of masonry set 1000 ft. back from the towers. The wire for the chains will be of the enormous strength of 180,0001 b. to the square inch. The bridge is for six lines of railroads, and the weight of the structure suspended to the chains will be 83,200 tons, or 26 tons per foot of the bridge ; but if the weight of the cables or chains themselves be added, this is increased to 109,000 tons. The cable will be 5609 ft. from anchorage to anchorage, and the weight over 6 tons per lineal foot. It is estimated that the bridge will cost about £7,000,000.

THE POWER FROM NIAGARA.

The total fall between Lakes Erie and Ontaiio is 329 feet, and is made as follows :—From Lake Erie to the head of the falls, 70 feet ; the falls, 161 feet; and below to Lake Ontario, 98 feet. Consequently the total power running to waste is more than double the 5,000,000 horsepower on the falls. An idea of the proportion that this total bears to what may be called the world's consumption of power may be had from the fact that it is computed to be equal to the total of all the steam generated power in the world. Tho geographical situation of the falls

with respect to nearness to the at present great power-consuming centres, is as hinted above, not quite all that could be desired ; but there are, nevertheless, several cicies within reach, electrically speaking, which will use an enormous amount. Buffalo mny be said to be next door, and Rochester is within easy reach. In the not too distant future we may expect to see the great electrical manufacturing works in Schenectady operated, as is meet, by transmitted power from Niagara.

KITES AND FLYING MACHINES.

A. 3 is well known, say a Hiram Sv Maxim, wheu one flies a kite the cordl holds the kite against the wind. The wind passing on the under side of the kite strikes it at an angle and raises the kite into the air. If the wind be blowing at a high velocity, say 35 miles an hour, the kite will lift from lib. to 51b. per square foot,* according to the angle at which it is held in the air. If the angle be slight, the anVount of . strain On the cord necessary to hold it against the wind wilL be found to be considerably less than the weight of the kite and the load which it is able to Ift, particularly so if the cord pulls in a horizontal direc ion instead of at an angle. It is -also' well known that if a kite be propelled in a calm through the air, say at the rate of 35 miles an hour, the effect is exactly the sameSuppose, now, instead of the CDrd for holding the kite against the wind or for propelling it against still air, that a screw propeller should be attached to the kite, and that it should be driven by some motor. If the screw propeller could be made to give a push equal to the pull of the kite, and if the machinery for driving it should be no greater than the weight thatthe kite would be able to carry, wa should have a veritable flyiog machine.

PHEASANT CHICKS.

A writer in Naturk reports some observations made on young pheasants newly from the shell. While acting to a large, extent instinctively, experience •seemed to be necessary in order to acquire dexterity in pecking, etc. "The young pheasants took no notice whatever of water placed before them in a shallow vessel. When I gave them water on the tip of my finger, they seemed to enjoy it, and one in particular drank eagerly from the end of a tooth-pick, so that an association was established between the sight of the tooth-piek and the satisfaction of drinking. But when I lifted this bird and others, and placed them in the shallow vessel, they made no attempt to drink from it. They learnt to drink from the vessel through pecking at grains of food lying on the bottom. They drank, however, less freely than chicks. The little birds showed ho sign of fear for me. They liked to nestle in my warm hand. My fox-terrier was keen to get at them, much keener than with chicks, probably through scent-suggestion. I placed two of the young pheasants, about a day old, on the floor, and let him smell them (under strict orders not to touch them), lie was trembling in erery limb from excitement. But they showed no signs of fear, though his nose was within an inch of them." '"-.',■•••

THE VORACIOUS STAR-FISH.

Down at the bottom of the pool a starfish crawls along. It seems absurd to talk of a star-fish crawling, but that is exactly what this star-fish is doing now. Yet he has no feet—that we all know ; and he cannot walk with the tips of his rays. Nevertheless, walk he does, and, notxmly that, he climbs, and even clings at times to the overhanging surface of a smooth rook. For every little pimple upon the lower surface of his body contains within it a delicate little fleshy sucker, and that sucker can be protruded, and used as an instrument of locomotion at will. We turn our star-fish suddenly over, and we see all these numberless little organs projecting—tiny, no doubt, yet each with a clinging power which the microscope traces to a cup and piston at its extremity. And all these can be Used alternau ; ly, v a3 a serpent;; uses the broad scale plates on the lower surface of its b dy, so th it motion in, any direction U possible. Without such power of motion it would he hird for a star fish to live, for be is a voracious creature, and, although he may not look it* is moreover a creature of prey. Small shell-bearing molluscs ha swallows whole, afterwards rejecting the shells ; large ones he kills and devours by the singular process of turning part of his digestive system out of his mouth and wrapping it rouud them, after the introduction of a few drops of irritating fluid has caused them to open. In this way even oysters are devoured • and indeed an oyster bed has few enemies more truly formidable than the star fish, whose annual ravages in a single fishery, incredible as it may seem, have been known to involve the loss of no less a sum than £lo,ooo.—Meodoso Woods, in Sun. day Magazine.