SCIENCE NOTES.

Otago Witness, Issue 2244, 4 March 1897, Page 48

SCIENCE NOTES.

• . • An important feature in the mechanical world is predicted by a writer in Engineering for the material known as ductile iron, now being introduced. Its tensile strength it represented to be 63,0001b and more to the square inch, and, after being heated to a dull red and plunged into cold water, it can easily be filed, showing that it takes no temper. Specimens are shown which have had portions heated and drawn out under the hammer, after being twisted cold, without fracture, and a notable piece of work oE the new metal is mentioned — viz., a heavy chain, of which the links were cast open, then joined and welded without

the use of flax; also valve stems, crankshafts, and other similar pieces, finished to pattern in a lathe and exhibiting surfaces without a blowhole, intricate castings, too, being reproduced regularly without failure ; while a very high percentage of losses has attended other methods of producing very strong castings. The main question, however, is that of cost, for there are foundries that produce castings which will stand all the above tests, but without being really cheap, as is claimed for this new method. . ■ At a recent meeting of the London Electric Omnibus Company it was stated by the chairman that they had an electric vehicle almost ready to put upon the streets, but that the adoption of improvements had caused some delay in completing it. There would be practically no noise and no vibration in connection with this omnibus, and it was estimated that the current for running it would not cost more than 2£d per mile. He put forward the hope that it would be possible to run these horseless carriages at cheaper fares than those now charged by omnibus companies. •. The death of a well-known football player from tetanus following a compound fracture of the forearm received while playing in a match forcibly recalls the risks attendant upon wounds into which earth or mud have found their way. Recent scientific investigations have clearly shown that traumatic tetanus depends upon the inoculation of wounds with a specific bacillus. This special micro-organism is found in garden mould ; it is also to be met with in the pus of patients dying of the disease. One curious feature about the bacillus is the extraordinary vitality of its spores, experiments having shown that while 80deg 0. is a sufficiently high temperature for the destruction of other micro-organisms, it is nevertheless the case that the spores of the tetanus bacillus are in no way discomforted by this excessive degree of heat. The plan would be a good one were each club to provide itself with a small box containing the necessary appliances for the immediate antiseptic treatment of wounds which may be received in the course of the matches. — Medical Press. • . • There have been sun-baths and mudbaths, sulphur- baths, and alcohol-baths ; but the colonr-bath is the latest novelty, and a positive fad among fashienable women with sensitive nerves. Colour-baths are said to reach closer to the real nerve tissues than any other means of cure. They are taken in small compartments, like vapour-baths. At \ the back of the patient is an aperture where ; a large slide of coloured glass may be inserted or removed at will. Directly behind the slide in each bath is a huge electric arc-light, that buzzes and glows in its white globe and turns the bath into a miniature lighthouse. The colours are chosen as one might choose medicines, and the patient sits bathed in a glory of the shade calculated to quiet her nerves or stimulate her vitality.

The treatment lasts from one to threequarters of an hour, and then follows 15 minutes' rest in a darkened room. • . • Th» inventor of the Wtaitby lifebuoy has lately reduced the weight of his buoy to about 501b, thu« making it capable of supporting 1501b of dead weight, or from four to six persons, iv ths water ; and he has also provided „it with receptacles containing another signal light, which the person saved by the buoy can light and wave aloft as a signal to the ship's boat which goes to his rescue, as well as a can of oil to still the waves. Other little vessels lodged in the buoy within reach contain rum or meatexaence, to be drunk as stimulants. Toe buoy is made of copper filled with cork. Attached to the buoy is a night-light, which yields a bright flare when it comes in contact with the water, and shows the position of the buoy as it floats on the sea. A metal cord round the outside permits the man overboard to catch bold of it. He can easily slip bis body into the ring, and take out the additional night light or the oil and stimulants placed in the receptacles. The buoy is usually kept in a box, which can be utilised as a deck teat, or hung along the taff rail of the ship at any angle. By a simple operation the box opens and launches the buoy into the water, where the night light automatically kindles without lobs of time. . • In the year 1849 some discovered at Monsummauo, near Lucca, in Italy, certain caves which are so hot and moist -that they can be used as Turkish baths, and attention is now being directed to the place as a health resort. The place was visited by Garibaldi and Kossuth for relief from rheumatic affections, it having been found by the inhabitants that the c&ves were beneficial for such complaints. The caves occur in a porous rock, and the air, saturated with moisture, attains a temperature of 88dcg Fahr. •.• Mr Greenhill, one of the professors at' Woolwich Academy, and one of the most ingenious of living mathematicians, has devised a curious and interesting spectroscope, to which he gives the name of a " gyrostat." Afew straight lines and curves printed upon a small flat card when looked at through this instrument assume a third dimension, and seem to stand out in space, taking the form of delicately-outlined globe* and other solids. The effect of the transparency adds to the beauty of the phenomena, the lines on the whole of the surface being clearly indicated. Mr Greenhill is preparing a description of the gyrostat for the forthcoming "Transactions " of the Mathematical Society. ■ . ' In ordinary compact factories with fairly efficient steam plant the grosß cost of the motive power — that is, of fuel, oil, and and water —is but 1 per cent, of the total paid out in workmen's wages. In ironworking, pneumatic power often increases a man's output of work 200 per cent. Then, if supplying pne man with his proportion of the motive power were by the use of air to increase his ; proportion of the motive power cost by 50 ■ per cent, it is evident we should then have a similar 50 per cent, margin for profit. As the actual cost is nearer 5 per cent, there is evidently a wide margin for extra outlay in machines or in their repair, which expenditure, per day or per man, is increased in the attempt to usef>neumatic power, but in the cost of such tools as drills, rhymer*, taps, boring cutters, &c, is not increased per foot run of actual work done when compared with manual labour. Thus it is clear that if the additional machinery a factory makes or purchases in trying to use air as a distributor of power is confined to such tools as will j beoften or fairly continuously used, this ] outlay is justified, and the cost of compressing relatively to total wages is so small that tools evidently wasteful in the use of air are economical, or rather show a net balance to the good, if the men find them portable. Busily adjustable, and handy to use, and their simplicity of make and freedom from repairs and breakdowns result!) in but few delays to the steady output of work. — J. D. Barnett. • . • M. Bontau, the discoverer of a method of photographing the sea bottom, has succeeded in taking several photographs of the vegetation that grows on the rooks by means of a watertight camera and flash light. Dressed as a diver, he takes with him to the bottom of the sea a barrel containing oxygen. A puff of gas from the barrel carries magnesium powder into the flame of a spirit lamp, j standing under a bell jar on the upper end of the barrel. Another puff actuates the pneumatic shutter of the camera at the same j time. He has found his method very useful j in exploring coral reefs. j • . • A glow worm makes light with about one-three hundredth part of the force used in ordinary artificial light. When men know how to make light as cheap, streets and homes will be as light as day for a mere fraction of what light now costs. This is near. Vacuum illumination without incandescence is already in full operation, and in a year or two should cut down the price of light to a sixth of its current cost, and in five or ten years light may be, like water, turned on in every house at will. ■ . • In a recent communication to the Societe d'Ethnographie in Paris M. Verrier treated of vegetarianism from the point of view of its moral and intellectual effect upon the nations who, either from choice or necessity, are to be classed as abstainers from animal food. While fully recognising the dangers of a too abundant meat diet, as well as the advantages of purely vegetable nourishment, the speaker nevertheless -felt constrained to come to the conclusion that Nature intended man to be carnivorous. The physical constitution of the human race is so ordered that to ensure the development of their higher qualities its members are of necessity compelled to become to a certain extent meat-eaters. The attributes that make for dominion and progress are but imperfectly present among the eechewers of animal food, and hence vegetarianism causes the downfall of dynasties and leads to the enslavement of peoples. If, continued M. Verrier, the Hindus, instead of following an absolutely vegetable regimen, had made use of meat in a rational manner, perhaps the British might not have found their subjugation such an easy matter. His argument was equally applicable to the Irish, who lived exclusively upon potatoes. As for the Japanese, with whom rice was formerly the staple food, the energetic nature of this people could not be cited in subversion of the rule laid down in his thesis. The reawaken- '

ing of the conqueror* at Pott Arthur and thf Yalu River was coincident with the establishment of a trade in batcher's meat throughout thoir archipelago.— Lancet.