SCIENCE, MECHANICAL INVENTIONS, ETC.

New Zealand Herald, Volume XLIV, Issue 13485, 11 May 1907, Page 4 (Supplement)

SCIENCE, MECHANICAL INVENTIONS, ETC.

, f^i;'if : 'l"r3*'T' n ■■■■"» HOW COAL CHANGES. It is probably not generally known that ' coal exposed to the atmosphere undergoes r chemical changes greatly affecting the 1 quality Moisture is the most powerful * agent in producing such change. { It; is a ! matter of common knowledge ; among tien: > engaged in the making of illuminating gas! > that coal which has been stored for a long time experiences a loss of hydrocarbons, and the effects of the change are shown in a diminution of the volume of the coal and in i a loss of illuminating power in the gas pro- ' duced from it. i; Such • chemical '■ changes oc- ' curring lin great masses' of coal' may even ; produce sufficient : accumulation of heat to ' cause spontaneous combustion, STEEL SAWN BY YARN. -What the drop of water does to the hardest stone is small compared to what a thread of yarn can accomplish. - ■ Major : McClaughry, - a prison governor, ; once found a prisoner who was supposed to be pounding stone, working away at one of the bars to an outside window. The man - finally , admitted what he was doing and induced to give a demonstration. A grating of the same description was placed \in his cell and a guard stationed over : him, to exact the proof of his statement. .With the limestone dust and silicate i from the stone pile, the yam from his sock and a little water this man cut the Ressember steel: bar in 18 working hours. With some fine emery, a chalk line, • and two wooden handholds ,to save his fingers he made the other cleancut of the bar in five hours, proving the matter to the warder's satisfaction. ; HOW THE MIKASA WAS SUNK. The loss of Admiral Togo's flagship Mikasa, as the result of an internal explosion,; was one of the : most startling events of the Japanese war; and the tragical atmosphere • which surrounded : the catastrophe was deepened by the fact that the Mikasa was more strongly associated in the minds of the Japanese people with the triumphs of the; war than any other ship in their navy. Moreover, there was i a sinister p. rumour, rather industriously circulated, that the loss of the ship was the work of discontented Japanese sailors. To at once j clear the navy of any such imputation, and solve the mystery of her loss, the Japanese Admiralty ; made an immediate investigation by means of divers, who reported that no trace could found of misconduct or neglect on the part:of the officers or men, the explosion having originated in .the port magazine containing 6in ammunition. :; When the vessel was recently refloated the Naval Department appointed another committee,; whose investigations have shown that the explosion resulted from spontaneous combustion, due to a . chemical change _, in the ammunition of the 6in magazine. That smokeless powder has always, been, and, in some of its forms, is : yet, liable; to dangerous decom- , position while in storage, is well known, and it is more than likely that other serious warship explosions and disasters may , have been due to this sinister and at one time greatly-dreaded cause. ' ■ DISTILLED SAWDUST. ' Many are the;uses". of sawdust. In i the , days I when the sawdust waggon made its , lumbering rounds; through the streets :of . most large --- cities two . commercial uses of • sawdust were to- sprinkle floors : and to . shelter lead pipes from cold and glass bottles: from breakage.;;' Nearly, every sawmill was a vat for the sawdust, and it was car- ( ried away free by anyone who had any use for it. In this era of the use of by-pro- ; ducts, sawdust has a commercial value. It is no longer given aWay, but sold. One of ' the ' recent uses of sawdust is (says a Kansas paper) its distillation, resulting in acetic acid,;; wood naptha, ; wood alcohol, and : tar. Sawdust may also be burned in special • furnaces, or mixed with other material ;. for '' fuel. Sawdust, when saturated with chemi- J cals", can be;effectively used in the manu- , facture of explosives, but it is more particularly in' demand; in paper-making; tlun for any other' purpose. - ';;"■ Such a thing" as sawdust on the floor of a room as" a - substitute for a rug' or carpet is now practically ' unknown. Sawdust has joined sand in this respect. ' Cotton felt has been■substituted for sawdust 'as a conductor of cold in winter. ': Gas can be made ; from sawdust. It is; also used ;; for briquettes, i.e., blocks of compressed sawdust and wood chips burned : for fuel. ; Even; ; in ; the •'.< protection of glassware against breakage sawdust has been superseded: by excelsior, sawdust being regarded as' too valuable for such use. RESCUE WORK IN MINES. An interesting practical demonstration of a new appaartus for rescue work in mines has been given by its inventor, Mr. W. E. Garforth, to the members of the Manchester : Geological and Mining Society. Mr. Charles ' Pilkingtoh presided. ; Mr. Gasforth's apparatus is in appearance not unlike that of the " get up" of a fireman, the uniform generally ; consisting of spectacles, cylindrical mouthpiece, a light, to,be switched on or off at will, on the breast, and a cylinder ; with a supply of oxygen sat the waist connected by a tube with the mouth. The mouthpiece has the recommendation of having a perfectly tight joint between the mouth v and the atmosphere, a supply of oxygen to last from two to three hours is also" guaranteed, and the carbonic acid gas is absorbed immediately it is given off. The weight of the ; apparatus, which can be taken to pieces, each part fitting on like a jacket and helmet, is almost 301b, though the inventor hopes very soon to reduce this considerably. '; The weight is equally distributed over the upper parts of the body, so as to inconvenience the bearer as little as possible when stooping or in other positions. The mouthpiece gives free play to respiration, and adapts itself to the face. The eyeglasses can be screwed off separately, so that, if the heat in the mine is- not very intense, each or both may; be dispensed with. In the discussion that ensued, in which the chairman, Mr. J. Dickinson, and Mr. John Galliford took 1 part, Mr. W. E. Garforth was complimented ;on his invention and on the great interest he had taken for years in this particular; kind of work. A plea was: also put 'forward: for some training station iin Lancashire where men could be taught to use.this new apparatus for rescue work.>-:,;. ; ' ::, : ", , . SHIPS THAT DO NOT ROCK. - " Poor sailors" and those who dread the discomfort of ;an ocean ; passage may ; take heart of grace. At the concluding meeting of the Institution of Naval Architects, held in London, Sir William H. White, late chief constructor to the British navy, called forth visions of steamers that do not rock. Sir William Vr-,'.» putting before the members the results of experiments with Dr. Schlick's gyrckopic apparatus for steadying ships. The experiments were carried out on a German first-class torpedo-boat, the appartus (a fly-wheel one metre in diameter, ; oscillating on trunnions, and making up to 3000. revolutions a minute) being placed in a compartment before the boiler-room. Your boy's gyroscopic top will illustrate the apparatus used. In all cases, said Sir William White, the practi- ; cal effect was ,to extinguish the rolling motion of a ship almost immediately. The : torpedo-boat was practically deprived of '■ rolling motion, and was simply subjected 'to heaving motions.; To ; use , Dr. Schlick's i words: "The waves seemed to disappear > under her, and she rose with a gentle mol tion vertically upwards, and sank again ' just as gently into the-trough of the sea ! without even spray coming on board to i any extent worth mentioning." Cross- > CnWmel ;: and coasting ; steamers of /| high • speed, continued ; Sir William, ' formed a i class in; which the steadying effect of gyro- » scopes would be of great advantage, and ; there would be no difficulty in fitting them. i It might be anticipated ; that experiments > would be made before long with gyroscopic t apparatus in destroyers and in the smaller - classes of cruisers. Professor Lambert said , people must not jump to the conclusion i that - sea-sickness was to be abolished at i once. :He had been told it was the heaving i motion which made people ill. Still, if the - transverse oscillation of a ship could be b minimised, it would add to the attractions - of; sea voyages and drive another hail into , She cpffin of any "Channel Tunnel, scheme..