SCIENCE NOTES.

Otago Witness, Issue 2690, 4 October 1905, Page 76

SCIENCE NOTES.

> — — ' —If criminals and other undesirables are killed by t.he aid of eloetrieity, it should also ' be, possible , according to .the Electrical Magazine, to mete out a like fate- to all these insects which, to the annoyance and 1 ' , 1053 of the farmer, take up their' abode in the upper strata of the subsoil. Though, perhaps, no one will deny the thporetical possibility of electrocuting a beetle or grasshopper, still, perhaps, he will wonder why - electricians have not already joined hands will the farmer for putting this valuable ally in his possession. The bodies of insects, and especially of crustaceans, present, relatively speaking, a high electrical re- ' distance, and wet earth is a good conductor of electricity. .It is thus obvious > iliKt v current of electricity, into damp soil, will do but little, harm to insects Swell- ' ing therein. Mr. Helberger, erigineer, of •Mono co, on working in an open_ field with' ' electrical machinery, found, on sinking into the ground metal tods connected up .to a "110-volt dynamo, that all the insects ' came out into the open air almost directly the current had' been passed through the earth. In other experiments an ordinary dynamo is mounted on a stout truck, and is drivon -by gearing' from the wheels of the vehicle "-itself, so that it . does not generate v elecV ( , tric'ity unless the vehicle is in motion/ current generated is. conducted _ to '■ earth by the metal wheels on the one side, and, on the other to a series of coppertipped brushes mounted on the rear portion of the cart, . and so disposed as to keep ' their tips a few "inches from the surface of the soil without corning into contact ; with it. Between tiie electrified earth- antf| the brushes- a continuous showier., of spark's took place, which'caused all the •unfortu.nate inhabitants of, the upper strata oLihe ' earth, xo meet with as instantaneous death': 'as! if, they had been, struck by lightning, It. .'will be obvious that, if the 'treatment be 'sufficiently intense, the insects .must be utterly destroyed,, but we fear that the , of current necessary to effect the ' operation would be" so Jiigh with this system ' its 'to render it hardly economical. ] ' — Sir Oliver Lodge has demonstrated by a series of beautiful experiments that light- _ ning flashes are of two" distinct kincls — when a cloud charged>jvith electricity approaches sufficiently neat to the earth to spark across the k intervening air-space, and there is quite a different type of flash when ' jjnother cloud intervenes between the j primary storm-cloud" ' and the earth. A | ' fiash darting between" the upper cloud and ( the lower neutralises 4he electrio tension en the upper, side of ihat cloud, and con- i -sequently suddenly releases the " eharga j which had been held in equilibrium on the lower >)r earth side. The flash which ■ Ihereupon darls earthwards is of the most I erratic character, and generally takes some j wonderful and' eccentric course which it is ' •lifficult to reconcile with the" idea of the i path of least resistance. ' It seldom or j never takes the shortest route, and as often ' as not she flash- is horizontal for a coht , Biderable portion of its journey. Even after it has struck a good conductor which J<?ad« straight to the' ground and Into conducting earth, it will very often leave it Rnd jump across to a much inferior medium. — Ohambarsls Journal. I — A new machine-gun; which appears to give promise of considerable utility, has recently undergone preliminary trials near London in a satisfactory manner. It is designed to dispense- entirely with wheeled transport, and is, in fact, more like an ordinary rifk in appearance and use, for the weapon a^d 250 rounds of ammunition m be carried by one man, who can also effectively operate it without assistance. The barrel is enclosed in an outer tube, in which it is free to slide to and fro, Bav<? for a spring- .rhich ordinarily keeps ?>, in firing position. , The recoil of the first shot throws jf. > backwards in the tube, and thereby actuates tho;'- mechanism by ■which the cartridge-case is ejected and tie second charge - brought into •■ place. The marksmain lies-Tipon th-j grou'odvin the usual position. 3 and' the. front of the gun is supported .by two light legs. The frun can be instantly ada.nted , for single, shots as an ordinary:: re-seating rifle or fpr. continuous firing, in which latter case its irate of discharge is 15 rounds a second.;, Its capacity is 25 rounds at a tirr.e,. acd "the insertion of -the clips containinsr „ the further : -charges can be so rapidly.. -,ef£eeted> that an .'expert soldier can maintain a. .constant fire f£f.- 300 a minufe. In "practice^ the marksIpianship appears £o" be" about /as good as that of ordinary infantry fire, 'in spite of the difficulties of main^ajning effective aim 'with a machine-gun fired froni the shoulder.' Thp. rate of fire being equal to that ,of about 20 'rifles, and .the casualty risk, Df course, only one-twentieth, it is obv'ous ihat the new weapon possesses at all events Dne great advantage. The arm is known j &s-the Rexer- automatic machine-sun, and it has been adopted in the Danish^ army, Whence come good reports of its behaviom\ — For manj' voav* in-vent<ii's Tiavf Deen trying (apparently without success) to deviso an improved method of rai-sing and lower?ng Venetian blinds. There has always teen a general idea that a blind which ocuJd be raised without the accumulation "o£ lathes at its lower end would be apprei«iated. One of the latest inventors collects the. lathes oi>e by one at the top of the Window by means of two vertical revolving spirals, or screws, that, passing through slots in ihe lathes, draw the latter up. The . spirals are operated through b^-vel gearing from a horizontal shaft. None tc'the previous improvements in Venetian i blinds Kave found favour in the eyes of the builder (the old cord and webbing arrangement is practically i/niver=al), cud whether this last device, which is un- ,

! dcubtodly ingenious, will prove any exGspI lion to tha rule venu.ns to be proved. — : London Si.n. S — The Times j-ocoid* (he discovery, byMr T. M. Davis, in the Valley of ihe Tombs of the Kings, Egypt, of a royal loftib which is quite intact, and has never been visited or plundered since .the age of the eighteenth dynasty. "When found, it was filled from end to end with the richest spoils of ancient Egypt. There wore muran<y-oascs encrusted with gold, hugs alabaster vases of exquisite form, chairs and boxes briiliani with paint and gilding, and a pleasure chariot with six spoked wheels, richly painted amd encrusted with, gold, the leather work being fresh as of ycfetorday. Beyond the coffins at <;he western end- of the tomb were lar.se sealed .jars of wine or oil ; boxes of black-pointed wood, each of which contained a piece of cooked meat wrapped in black muslin ; also, four canopic jars of alabaster in which the entrails of the deceased were deposited. Gold is plentiful, and an inscription say& h was brought from the south. This tomb was the burial-place of Yua and Thua, parents of Queon Teie, the wife of Amonhotep IIT, and- the mother of the heretic Kiusr Amon-hot^p IV of the eighteenth dynasty. — There is no finality in invention. s.vd present; achievements but faintly indicate "the wonders that will ba." Marvellous as arc the linotype and monotype as pieces of mechanism, a method of enormously multiplying the quantity of the work they perform has been suggested. Some year's ago an American scientific paper contained a statement that an inventor was uei feeting a mechanism by which one operator could set the type at the same time for a number of papers in different cities. To do this, th© lintoype or monotype would be so arranged that as each letter on the keyboard was pressed -n electric circuit would ■be connected, and a corre spondiaig mechanism would thus be electrically operated elsewhere, as the manipulation of a telegraph instrument in one city influences a similar instrument hundreds of miles- away. Though startling, no one can say that the suggestion is impracticable, and the time may come when one compositor in. the metropolis will set the type for the general news for every paper in the kingdom.— Dublin Daily Express. — Less than a hundred years ago cur grandfathers knew not so much as the .meaning of the. word railway. It is possible that .less than a hundred years hence ,our ' great-grandchildren may be equally ignorant — for some new means of locomotion 1 may have eomo into being. A very interesting discussion as to what the future holds in store for locomotion in general is published in the August Pearson's Magazine — and many eminent men, inventors, philosophers, and engineers, give their views. Sir Hiram Maxim, the famous inventor of automatic firearms and countless other marvels, expresses his ideas on the subject as follows:— "In the immediate future we shall have electric trains, running at 100 miles an hour. When a thing is both possible and highly desirable, and when all the material for .naking it is at hand, it is something less than prophecy to piedict that it will soon come into use. At the present moment we can go to Brighton in a fast train in an hour, on a railway that has cost a great deal of money, spent largely on grading or levelling. But it is quite possible to construct an electric railway that would run on the giound's surface— up and down hill— and would enable us to go from London to Brighton in. from 20 to 30 minutes. So I think it will not be very long before we have very rapid electric trains. Then, again, internal combustion engines, driven by the light products of petroleum, have been made very light and efficient— so that motor cars, in a large degree, will ■supplant horse-driven vehicles. But, more than all, we are bound to ha\ r e aerial navigation during the first part of the present century. living must come. It is not only highly desirable, but it is possible For- the first time in the history of ihewold, all the materials are now available — thanks to the millions of pounds spent in experimental works on motor care. We are in possession of an ideal force of energy. We ars now able to obtain engines thai develop the power of a horse with the weight of a common barn-yard fowl — whilst strong steel and_ aluminium tubes ran be obtained in all dimensions. It only requires 'a lot of time and money' in order to pro'luee a machine that will navigate the air. But flying-machines will not be employed for carrying bricks or freight generally— chiefly they will be used for military .and sporting, purposes. The cost of experimental work is great — far too much to be borne by am individual, unless. a Carnegie ir a Rockefeller. In time, doubtless, some very wealthy nian will come to the ad of scientific engineers, and then we shall have a machine that will make a new geography necessary and new laws regarding international coir-merce. If the* British Government could be induced to spend a quarter of the money that the French Government has spent on experiments, it - could b& in possession of a flying machine within three years. For £100,000 I myself would build a flying machine. (I have spent £20,000 already on experiments, but my wife has made* me premise not to spend any more !) £100,000 would be quite enough to buy all the material and the very best assistance in the woild, which happens^ at the present moment, to be available in England."