SCIENCE NOTES.

Otago Witness, Issue 2403, 22 March 1900, Page 58

SCIENCE NOTES.

— An Austrian savant has declared that the human TOain contains a "name centre." He says that it is the office of this cell to retain names. A striking case which would seem to confirm, this theory recently occurred at Cleveland. A brakeman was shot by a conductor, and afterwards could not remember the names of persons or things, although he could perfectly .well describe the functions of all articles exhibited to him. The surgeon probed for the bullet and found it in the exact spot necessary to effect the remembrance of names, according to the Austrian's theory. When the pressure on the brain had been relieved, the patient remembered names, and told that of his assailant.

— A phovoheliograph has just been added to Harvard Observatory. Its construction and erection have been watched with interest by both astronomers and scientific photographers all over the world, for the instrument is of ingenious arrangement, and of such huge proportions that notable results may be expected from it. It has been built by Professor Edward C. Pickering, director of the Harvard College- Observatory, who was the designer of the remarkably successful Bruce telescope, now stationed at Arequipa, Peru. The photoheliograph, strictly denned, is a telescope for photographing the sun. It is jalso used, however, for making pictures of bhe different planets, and especially of the moon. There are many different kinds of photoheliographs scattered about the world among the various observatories ; but nearly all of them follow some well-known rule of construction. Profesor Pickering made a radical change when he built, several years ago, the instrument called the Bruce telescope, which had the enormous aperture of 24in, and the focal length was six times the aperture. This instrument, since it was placed in the marvellously clear atmosphere of Arequipa, has done astonishing work. The best photographs of the planets ever made have come from its lenses. The astronomers who have it in charge are now making charts of the sky, some of them of such fineness that 400,000 stars appear on a single plate. But the new photoheliograph the Harvard astronomer has built is quite different from anything ever attempted before. It will be placed in a perpendicular position, and will tower 135 ft into the sky. This enormous focal length will be combined with an aperture of only 12in — just half the aperture of the Bruce telescope. The Bruce instrument was different from othe^ instruments in the Bize of its aperture; the new photoheliograph fis different from others in its extreme focal length. The Bruce instrument brought about important discoveries in astronomy ; the photoheliograph is expected to accomplish at least as much more. The suneriority expected of the new instrument over all others is in photographing what the telescope lenses ghow. Since the instrument is placed vertically, a mirror is used to reflect heavenly ob-

jects on the plate. A clock arrangement turns the plate at such a speed as to counteract the movement of the earth. The new instrument was paid for by anonymous subscribers, but its cost will not exceed 10,000dol — one-fifth of what the Bruce telescope cost.

— Elisha Gray, the well-known American electrician, and Mr A. J. Mundy, of Newton, Massachusetts, have brought out a method of telegraphing through sea water by submerging an electric bell to give sound signals at the sending station, and also a microphone in circuit with a telephone to receive the signals at the other station. The bell and microphone are sunk deep enough to avoid the disturbances of the surface waves. The vibrations of sound are transmitted through the water from the bell to the microphone. The electric bell has a pure, unvarying tone, easy to recognise, it being tapped a given number of times per second by means of an alternating current. This .note is interrupted by a sending key according to the Morse code. Five miles is considered a short range for the system. We may remark (adds the Globe) that Mr Gray and his colleague are not the pioneers in such a telegraph. The idea was tried in this country by a naval gentleman, and it has been familiar to us for some years, but it ip possible that Mr Gray has made a practicable apparatus. Sound travels much faster through water than through air, and such messages would be independent of the weather.

— One of the bills for electrical supply schemes to be dealt with during the next session of the Imperial. Parliament affects the whole of Lancashire, "except that part which lies to the northward of the river Ribble." The company, which is to be shown as "The Lancashire Electric Power Company," will have a share capital of £3,000,000 and a loan capital of £1,000,000. The share capital will be divided into 300,000 shares of £10 each, which may be divided into "preferred half shares" and "deferred half shares." The profits are to be regulated by a sliding scale on a 10 per cent, basis — that is to say, the company are to be entitled to pay an additional 1 per cent, above 10 per cent, in respect of every 5 per cent, charged below the maximum rate allowed by the bill.

—In his address on the occasion of the celebration of the seventy-fifth amiiversa \v of the Franklin Institute, Philadelphia, Fiofessor Charles F. Tlimes, referred to a statement made by Dr Crookes that "some bodies without special stimulation are capable of giving out rays closely allied to, if not identical with, those of Rontgen, and it would almost seem, from the important "esearches of Dr Russell, that this ray-emittir.t? power may be a general property of matter, for he has shown that nearly every substance is capable of affecting the photographic pJote if exposed in darkness for a sufficient time." The list of active substances is a long one, to which a recent investigator has added the human body. The rays para through many opaque substances, and are checked hyopi'iwt. They excite fluorescence. Already toey hove led to the discovery of a new met-il ly Madame Curio, named polonium, possesssinvc 400 times the energy of uranium, which has hitherto held the highest place. This energy seems to be without exciting cause, and without perceptible diminution. If radiant energy, may not perfumes, he suggested, which have beep regarded as material emanations, be of the name character, and the rose emit rays that will affect a properly sensitised plate? I like this theory immensely ! What a vast field it opens out to the coming photographer ! I can perceive that some time in the future we shall at last be able to apply the delightful aroma which arises from the River Aire to a useful purpose, and that when once we have discovered the proper sensitiscr, we shall not require a clear atmosphere, but a "big in which to make our pictorial photographs. — Professor E. L. Nichols and E. Mcrriit. who have been studying sound phenomena together, substituted for the mirror a long photographic film arranged on a cylinder which was made to rotate at a high velocity. With the film and a specially-constructed lamp, which gave an intensely bright light, it was found possible to take photographs of the vibrations made by various sounds. It was clearly and unmistakably demonstrated that the sounds of such words as "die" and

"sigh" made vibrations that were very little dissimilar, while words that bore no similarity of sound produced entirely different vibrations. The experiments were carried to the extent of connecting a series of photographs, and testing the possibility of reading it as a line of ordinary writing is read. When one of the experimenters had become familiar with the various, forms of the records, a series of these was taken on one plate while the man who was to make the test was absent from the room. The photographic • plate was then taken to him, with the very interesting and highly satisfactory result that the sounds were read off like print.

— A new method of making a durable artificial stone for paving purposes has been successfully introduced in Germany, and is likely to find employment in many countries. The basis of the pavement is, like that if irr.uy other systems, coal-tar. This is mi::-?d v. ith sulphur and heated, and to the plastic mas--is added a preparation of lime. When cold, the compound is broken into fragments and mixed with glass or blast-furnace glass slag. Subjected to heavy pressure, the powder i& moulded to any form required ; and it is found that its resistance to wear and tear is fully half as great as that of Swedish granite. The other advantages claimed for the paving is that its roughened surface gives a good foothold, that it resists changes, ot tempeiature, is not noisy, and is easily kept clean.

— The magnetic concentrator that has been used since January, 1898, at the Monteponi mine, in Sardinia, consists essentially of a fixed horseshoe electric magnet, placed v/ith its poles downward. Below the poles is an endless rubber belt, a foot wide, at a distance that may be varied at will. A hopper feeds on to the belt a thin layer of the material to be treated, which is carried forward by this belt at a velocity of l^ft a second. In order to collect the portion attracted by the magnet, a second endless belt moves horizontally in a direction at right angles to the first, close to the poles of the magnet.' The magnetic plant at Monteponi treats in 24- hoiirs 24- ton? of material, previously submitted 'to a reducing roasting. The material consists of silicate of zinc more oi less ferriferous, limonite. and zinciferous dolomite, materials of almost identical specific gravity. In the raw state the material contains on an average 22 per cent, of zinc, a percentage which is brought up to 30 by roasting. The magnetic concentrator extracts about a third of iron ore, assaying 10 per cent, of zinc, while the remaining- product is brought up to 40 ncr cent, of zinc. 3y treating this product in hydraulic jiggers the lime and magnesia from the dolomite are removed, and the final product — oxide of zinc — contains 48 per cent, of zinc.