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Otago Witness, Issue 2426, 12 September 1900, Page 62

SCIENCE NOTES.

— The old saying about "midsummer madness" seems to have had some tiuth in it. Tho Academy of Sciences, Paris, and other learned societies find tluit in July and August the largest number of absurd and insane projects are submitted to them, and from the statistics ot lunatic asylums in Switzerland Dr Meicier shows that mental derangements reach their maximum in the heal of dimmer, though bodily ailments are Usually at a minimum then. Moreover, the cur\ c for suicide in Sw ltzerland is twice as high in July and August as it is in December, r-n observation which agrees with the curves for = uicide in some other countries. Crime has also been shown to attain a maximum in America during the hot season. Apparently a mere drought — that is, a low hygrometric state of the atmosphere — increases mental trouble and suicide.

— The time must come when our coal supplies will fail, and before that evil day arrives it will be necessary to find some other source of energy. The heat of tho sun or the tides of the ocean may perhaps be utilised or, as Sir William Preece recently pointed out, the vast store of energy existing in the heated interior of the earth may be drawn upon. In descending from tLc surface of our globe, the temperature becomes hotter and hotter, until at a distance of about two miles the degree at which water boiL is reached. By suitable thermo-electric appliances it I would not be impossible to use this internal | heat to produce electric curreiiU ar.d thus convert the lost energy of the earth's interior into a useful form. Electricians ha^ c successfully utilised the power which presiously ran to wa»te in watsrtiils, and the time is probably not far distant when borings will be made in volcaivc districts i*nd the earth* smouldering fire-? will be hai'iie^ed to the wheels of industry. Another possible source of energy in the future is the ether which peimeate- and Kin-rounds everything, which transmit- the .signals of tho wireless telegraph, and which we are only now beginning to know. There is every reason to believe tl>at every oub'c inch of this omnipresent ether contains enough energy to keep hundreds of horse-power going for a year, if we could only get at it. When ■>t;hi& supply of energy is tapped, we shall 'be independent of all other sotuce=.— Leisure I Hour.

— The liglitn lag-rod man has for several generations been travelling through the world convincing the residentb of towiio, \illages, and farmers that he had that which they could not afford to be without. As> a consequence house.-, barn?, stores, granaries, and all other buildings in which human beiog*, live stock, or portable property are kept have been .fitted with devices warranted to afford tho electric fluid safe conduct to the ground. Now the Electrical "Re\ie\v eiate? thai '"the lightningrod, no matter what pattern, or whose invention ; no matter «whal it co&t, cv w hat the lim-ber-jawed dealer said of it, ha.-; no more influence over the course of the lightning than the colour of the paint on our house-."' ' — In America wire fences aie now regarded by agriculturists ps "death-irap.-s " because many cows and other domestic animals winch happen to be near them axe killed by lightning. Thpre is, however, a means ol rendering them harmless. The director of the Weather and Crop Service of lowa recommends connecting them to "earth " by wires after the manner of lightiiiiig-rocK — A new developer has lately appeared which is said to give good results, and be equal, if pot superior, to hydroquinone. The body, which has received the name of adurol, is a derivative of hydroquinone, and seems to have all the good properties oi that developer, without its defects. It requiies but a small quantity of alkali, and the potassium carbonate may thus bo replaced by sodium carbonate, which i^ less corrosive, while the u;e of cau&tic alkali becomes nece^ary. In spite of the small quantity of alkali, the image comes up more quickly than with hydroquinone, and it is also to be remarked that low temperatures have no appreciable influence in retarding the development of the image or details. The principal quality of adurol is iU great developing power, which is not equalled by, hydroquinone even with the use of caustic socla ; it has the valuable property of working up to the end of the development without causing fog upon the plate, which roncWs. it superior to many other de\ claviers in this respect. The image appears noimally in about 20 Fecond«, and the development is regular and uniform ; after about four minutes it has gained the desired intensity. The reduction of silver takes place not only in the stronglyexposed parts, but in the details, which come up regularly as the development proceeds ; in this way the final lesult is> a plaie which presents a iiarmonius appearance, rather soft than hard in quality. It s apparent that oudriol may be u-:ed with shorter exposures than when hydrochinoii is used, and may thus be of value for exposures by dim light, for rapid, instantaneous w ork, X-ray exposures, etc. Bromide of potassium is an excellent relarder for this developer, but it may be used in smaller proportion than usual. — Scientific American. — In point of actual rote of construction, the Siberian maximum is far bsliind the American one, though, it must be considered fast under the cii-cuniotaucc!-. Three miles and lhre"-qur.rtei's per day is the highest ever reached by the Russians — a poor record when compared" with the 104 mile., credited to American brain and Chinese labour on the tSan Francisco section of the American line. But the Americans, on the other hand, took neaily seven years to complete a distance of 1800 miles, whereas in Siberia nearly 1000 miles, beyond that amount w;<s accomplished in le.-s than eight years. In sheer length, the Trans-Siberinn wi>l be almost double thit of the Trans-Americaa Continental railway. The maximum altitude oL 3608 ft, overcome by eery gentle gradients, while proving the Yablonoi or "Apple -Mount r.iiib " (so called from there rounded contours) cannot be competed with the giddy precipices of tL? Sieira Nevada, or the 0500 ft; ascent of the Rocky Mountains. And all-hough the Siberian Plains are, perhap«, cs scantily populated as were tho^e of the Far Wp-1 in 1860-70, they include no such waterier tivcts a D the Utah and Nevada wildprne^e-. Leaving Transbaikalia and Mtu.churij out of the question, the Siberian line was an exceptionally o.^y one from an engineering point ol "Beyond the Uralo the iails could bo laid in straight lines over immense pi tins. Between the Obi and the Yenisei there are but gentle undulations to be c\ereomp. After crossiu? the Yenisei , a aeiies ci hills— never exceeding 2000ft— arc traversed at light nngle^. in the A\holo distance trim Oheliabinsk to Irkutsk, Lake Baikal nearly 2000 miles — no single tunnel occni'D, no gradient is hteeper thm 17^ in 1000, arcl no curve .-harper than a 270 yards radius. Convict labour was found un?atisfacloiy, but the Russian pea^-uit followed the work, obtainnig short periods of release to -\i-it hia home. A few luiolibh engineers are employed on the ice-bvc ikev ond dock at Lake Baikal ; but otherwise all officials arc Russia 11 . — Engineering. — "A worm will turn," as we are often reminded, and fcoru^i^ifes j>y very; robust Qhli&-

tians not at all resembling worms in meekness; but the question arises, Does the worm lesent the injury done to it? Does it even feel any harm? Its body turns, but thai is not a certain proof that it actually feels pain, for there are ''reflex actions"' oi an automatic order, which though designed, if we may use the word, to protect the creature, may not necesaarily involve pain. The sensitive plant shrinks when you touch it, but we do not suppose that it feels shy or hurt. It is possible that many of the low er animals feel very little, if any, pain, though by their actions it would seem they did. The late Professor Norman, of the University of Texas, maintained that animals up to fishes of the flounder species did not feel pani, but Professor Dearborn, of Harvard, questions his conclusion.