SCIENCE NOTES.

Otago Witness, Issue 2565, 13 May 1903, Page 64

SCIENCE NOTES.

— There may come a day when, if the dream ;f the scientist proves prophetic, we catty have an atmosphere without smoke or diit, and 8. sky as clear and blue as hangs over Monte Carle or beautiful Florence. This delightful consummation is consequent on the invention of an Italian scientist, .whc has been giving his views to a representative of the Westminster Gazette, and to whom _he showed the marvel, which is to produce ec great a revolution — a small cylindrical tank which throbbed gently like a motor at rest. Tl« tank was contnected .■with ihe chimney by a zinc pipe, which conducted the escaping smoke into the cavity of the tank, where, after being robbed of its noxious properties, ;.t; .t was allowed to escape as clear and white ac steam from an 'exhaust pipe. The whole apparatus, including the electric motor which supplied ■the power, occupied no more than a square yard of space. "With this apparatus," eaid Signor Mugna, the inventor, "we can purify 2001b of coal smoke per hour. Through this pipe we take the smoke from the chimney <by means of an electrical fan. At the '.bottom of the tank there is a laye-r of water, and the smoke, is it enters the tank, is forced lown. by an ' agitator ' until it is mixed with the water, which is being driven iby the centrifugal force of the ' agitator ' against the sidee of the ylinder. All the 9>eavy matter is thus deposited, aiot only the coot and grit, bu' the sulphuretted gases, 4he carbonic acid gas, which is so dangerous to health, mmonia, and other ingredients of an undesirable character. The efnoke, which still escapes, ie white and plean, as you can see, and soon becomes dissipated in ihe atmosphere. But where (the full value of my invention comes i<n." said the inventor, "is that it is economical. The cost of running the machine ie 1 1-3 g>ei cent., but the 5 per cent, of the coal •which Is precipitated to the bottom of the itank can be used md dried again it coal cakw. That is a great saving of material which at present disappears 'tnto thin air. Then, again, there are by-products, which »?an be converted into aniline dyes and eaccharine and even into physic. So, inJtead of an expense, my invention would •real!y be a great woromy." A piece >f .wlv'e papei held over the chimney showed aio signs of dirt, and the Signor claims that "the nvention is already being used on the Ita] railways with success. Altogether &ig> Mugna has spemt seven years' labour »nd half a million francs on the apparatus, j — Studies of the flights of birds are of deep interest jn connection with Aie problem of aerial navigation with machines heavier (than tho air they displace. Balloons float, and are therefore more or less at the mercy lof the wind, so that no flying machine dependent upon the lightness of a bag of gas can be regarded a: a jompletely successful sneans of navigating- the' air. Birds are fteavier thaD the air, yet they are able to iris© from the ground and fly at will by ithe expenditure of muscular energy, and as {Nature's machinery is usually perfectly adapted io the work it ha to do, it forme /the best model foi the construction of artificial machimes. The simplest kind of flight rto Imitate is that of soaring, by which many Jbirric are able to keep their weighty bodies Kn ''c air with very little motion of their fair The largest soaring bird known to )Bci' v 2 is. the pterodactyl, or flying reptile of :■ past geological age. This creature renpreeents Nature's greatest flying maohine. {Next to it come the condor and the turkey Jbuzzard, both of which are soaring birds. (The weights of these birds are 'known, «nd Jfche "izes of be wings; ant 1 it is possible Jfco estimate approximately the muscular /energy expended when in flight. In the Jcase of the pterodactyl the weight of the icreature was probably about 301b, the cup- ' sorting area of wing 6urface about 25 square

feet, and the jnergy required to keep afloat in 'the air less than the four-hundredth part of a horse-power. Professor Langley lias constructed a small steel flying machine of the same weight, and with double the area of -supporting wing surface, but a motoj- of one and a-half horee-power was required to make this artificial bird soar for distances from half to three-quarters of a mile. Nature's largest flying machine has therefore not nearly been approached as regards efficiency. — Leisure Hour for March. —Of all .übstanopf. in common use, glass i the most brittle, a fact which has been crystallised in the old proverb about etano-throwing ; but unless the report is altogethei erroneous concerning a now description of glass invented by 2>lr Louis Kauffeld, of Matthews, Ind., U.S.A., there will come a time in the near future when dwellers in glass houses can indulge their stone-throwing propensities to ..'heir hearts' content without any Jamage to their homes. The new glass will act break or crack even when submitted tc the roughest treatment. For example, a lamp chimney of tho now material, aftei being chilled in ice-cold water, was put on a blazing lamp without injury. The same chimney was placed on a pas-stove until it softened, but it would not break ; cold watei was placed in it, and brought to the boil, but no harm came to it. Next it was used as a hammer to drive nails into a box, and even this did not break it. Finally it was treated as a mould, a hot glass chimney being blown within it, both mould and new chimney coming out of the ordeal uncracked and unscarred ! These various experiments are described and illustrated in a recent number ol the Scientific American, and there is no reason .o doubt their .ruth. Malleabk glas^ has long been the iream of enthusiastic inventors, and if it )an be produced at moderate cost it will have many useful applications. — The large dark areas on the moon were formerly /onsidered to be seas, and they 'till bear the name. It is lot improbable that they aie beds of former seas existing at very remote periods of the moon's existence. These maria, as .hey are termed, are now dry, level plains similar to deserts on the earth. It has long been held that the moon has no atmosphere or water, and consequently no vegetation whatever, but this conclusion is by no means considered final. In the "Annals" if the Harvard College Observatory for 1900, Professor Pickering, ihe distinguished astronomer, enters into this matter in great detail. After long and exhaustive examination, he arrives at the conclusion that the moon has a slip-lit atmosphere, and that there are indications that water has not yet probably dieappeared. He speakß of 'Tills" and of "river-beds," and enumerates 35 of the latter. It ie improbable that the mocoi was ever a world teeming with vegetable and animal life like our own globe, but probable that it was always, even in its best days, a comparatively barren and arid waste. Looking, however, to the marvellous adaptation of life to itR environment that wo find on the earth that .ye livo upon, under conditions previously considered impossible, we may rc-asonabb infer that life, at least in lowly forms, in bath animal and vegetable kingdoms would be found on the moon. — From "Glimpses at the Moon," in ihe Leisure Hour. —An Italian professor is said to have invented a remarkable instrument which 1 jompletely solves the problem of lighting up the depths of the sea. Even with a cheap apparatus the inventor is said to havn lit up with astonishing brilliancy .he bed of the sea at a of 290 ft for a distanoe of 8 furlong, and it is claimed that with more efficient instruments this distance could be enormously increased. If authentic the discovery will revolutionise 'ncipicnt theoTies of submarine warfare. On tho one ■hand, it will help the submarine by light- , ing ite curse, but. on \q other, the

| battleship will be able to see the submarine : much farther away than it can at present. — This year will be a memorable one in the history of aeronauts, for the reason that so much attention has been devoted .k> i3O-called flyimg machines, which are in reality balloons ovei which, by jertain mechanical appliances, the occupant has a limited amount of steering power in the absence of wind. Two of these frail machines have come to grief in France, and thei. drivers have been killed. The machine In which M. Santos Dumccit sailed round the Eiffel Tower at Paris was mysteriously injured before a projected ascent at the Crystal Palace, London, md no more has been heard of it. The English balloonist, Air Stanley Spencer, built a dirigible balloon to take i-ts place, and he made some 30 preliminary trips round the Palace grounds before attempting a bolder flight over London. This at last he has ucceeded in doing, his machine starting from Sydenham and reaching the ground it Harrow, ■after a run of about 20 miles. fins experimental trir is the most successful of its 'kind yet made, but it brin^ us no aieaxer to the solution of the problem of aerial navigation. — In an article in the March Cornhill on "The New Chemistry," Mr W. A. Shenstone speaks of the strange theory which has gradually been built up as 'the result of the phenomena of electrolysis, or the splitting up of a substance into its elements by an electric current. This process is one which has long been used in manufactures, and enables metals readily to be- coatd with an almost inconceivably thin layer of gold or silver. But ite meaning in Tegard to the great problem of the physical structure of the work! we live in is enly just beginning to be understood. Formerly it was thought that tho molecules of euch a substance as hydrochloric acid must be held together by an enormously powerful chemical attraction, because of the great ffecfc it produced in breaking up other substances. Now the contrary is seen to be the :ase. If two electrical poles are introduced In a weak solution of thi« or any other "electrolyte," atoms of one of the constituents collect at one pole, and the other at the Other. Even the weakest current will bring this about, so that it is seen that many of the molecules, or atom-combination, are not whole in the water, but that the separate atoms move freely about, the two kinds, however, being charged with opposite kinds of electricity. If the water be carefully evaporated, che wandering atoms will mate again in the complete 6iibst£mee, but the most trifling electrical attraction will draw them apart while in solution. In this way, a compound containing gold can be broken up in a bath, and if a metallic- ornament be made on one of tho poles of the battery it cam be coated with gold omly one atom in thickness ! Th« theory suggested (observes the Daily News) is far more surprising than the ingenious experiment itself. For *hat j it really means is this: that the atoms Df j which the world is built jp are held to- ' gether simply by electrical attraction ; that "ohemical affinity" and electricity are for.-ns of the same thing. The dynamite which , will wreck a city in an instant is simply a preparation by which we can oall into .ction a concentrated thunderstorm. The >ternal i Alps are held together, atom by \tcm, by i an attraction like that with which the magnet ; draws iron filings to itself. Let but this invisible force fail us foi an instant, let it ■ be lacking in the regions of space into which our solai system \u flying year by year, aud earth and sun and moon and planets would sink into ineffable nothing- : ness, lose form, find substance, and identity, . and fade into nebula lightei than air. • — According to facts given in Engineering', the metric system is no new thing. James ; Watt compla:med ot the irouble he ex- ' perienced in reducing weights and measures when comparing experiments made by Lavoisier and Laplace with results obtained by others. He then suggested that 't would be a good thing to introduce a *aound to be used by all philosophers, and that this philosopic pound should be divided iecimally into tenths and humdredths. He further proposed that all elastic fluids should be measured by weight, the standard being one-tenth of a philosophic pound. He concluded his letter by suggesting that the foot should be fixed by the length of the pendulum, and that the measure of weight should be derived from the foot. Later on —23rd November, 1783— Watt wrote to M. de Luc on the same subject, saying that Mr Whitehurst was at work on a philosophical measure, from tvhich he meant to ieduce a poiund to be divided decimally. It appears from these letters that Watt foreshadowed ihe cardinal principle of the metric fystem, which is the determination of all fveights and measures from a single standard of length. Mr Alex. Siemens has pointed out- that probably Watt wae directly responsible for the movement among French scientific men in favour of a n?\v system, for in 1786 he and his partner, Boultoci, went to Paris, and i made .he acquaintance of most of the lead- i ing men there. At anyrate, in 1790 ; Prince Talleyrand proposed to the Constituent Assembly of France that the many systems of weights and measures in use in that country be changed foi a single system, ro be founded on the length of the pendulum, and to be divided decimally. Phis was adopted by the Assembly on 17th March. 1791. sanctioned by Louis XVI, and a National Commission — including representatives from Spain, Italy, the Netherlands, Denmark, amd Switzerland — sat to settle the linear standard to be fixed. The Commission did not adopt the seconds pondulum as tin standard, but chose the length of a quadrant ot the meridian, and a ten-mil-lionth part of this quadrant was called the metre. The growth of intercommunication : be-tweem nations subsequently forced upon other countries the question of reviewing their weights and measures. — The traveller on the great Ameriraai railways has scarcely a want or a desire, natural or artificial, unfulfilled. He ileep=, c-at.s, reads, writes, smokes, amuses himself, tra.nsart€ bueiiKVs, bathes, and is shaved with the utmost comfort and safety while speeding ncr the country at the rate of 50 miles or more per hour. Advice ao Mothers. — Are you broken in yenr rest by a sick child suffering with the pain of cutting teeth? fio at once to a chemist and get a bottle of Mrs Winslow's Soothing Srr.up. It will relieve the poor 6uffcrer immediately. It is perfectly harmless and pleasant to taste, it produces natural, quiet sleep, by relieving the child from pain, and the little cherub awakes " as bright as a button." It soothes the child, it softens the gums, allays all pain, relieves wind, regulates tho bowels, and 13 the beet-known remedy for dysentery and diarrhoea, whether aruing from teething or other causes. Mrs Winslow'a Soothing Syrup 23 sold by Medicine dealers tTerjwhere.