SCIENCE, MECHANICAL INVENTIONS.

New Zealand Herald, Volume XL, Issue 12272, 16 May 1903, Page 6 (Supplement)

SCIENCE, MECHANICAL INVENTIONS.

HINTS FOB INVENTORS.

The president of the Society of Engineers , states that a machine is needed which will sweep mud or dust from a. road and transfer it to a vehicle 'for removal, so as to save the heaps and loading into vans by manual work. Specially-constructed vans, which would spread water, to which a disinfectant had been added, in a fine spray on the road surface might bo tried; and, perhaps, a machine that would take up the dust from the road by exhaustion, and discharge it into a receptacle containing water, might at some time be invented. Pavements which add little to the noise produced by traffic were necessary in the principal streets where business was carried on; and although the noiseless shoe for horses did not seem to be practicable, improvements should be made in the construction of vehicles so as to diminish the clatter made by them.North Mail. EFFECT Oh- WIRELESS TELEGRAPHY. The possible effect of wireless-telegraphy Bendiug-slations upon the metal pipes and framework of modern high buildings is discussed by the Electrical Review. Says this paper:—"We have here vertical conductors of a height approximating those of the usual sending wire, and should the electrical constants of this pipe give it a period of oscillation approximating that impressed upon it from the sending-station, will not this pips become ' charged' and who can tell with what effects? Tlu probable effect of a powerful wireless telegraph sendingstation within a large city certainly seems to be a question deserving of the most careful and thorough consideration." LIFE OP LOCOMOTIVES. Hie life of an express-locomotive in .England, according to the Echo des Mines (Paris), is estimated at 25 years; that of a freight-locomotive at 26, that of an ordinary passenger-engine at 25, and that of a switch-engine at 27. "In the United States the life of an express-locomotive is IS years, of a freight-engine 16 years, of a passenger-engine 19 years, and of a switchengine 22 years. In 18 years, however, the American "machine has run 2,000,000 miles double the average travel of an English locomotive. . . In other words, tho American engines live hard and therefore die young. in France locomotives really live to old age : the average life is 29 years." TREATING TIMBER. A considerable amount of interest has been aroused," says the Scientific American, "by lie announcement, as the result of a prolonged series of experiments, of a method of so treating timber as to secure even from soft wood a largely increased toughness and bardness. The process is described as one »f vulcanising, comparable in some respects ,/ith Bessemcrs process of converting iron into steel, and is the invention of Mr. Powell, a Liverpool merchant. The treatment to which the timber is subjected is, roughly speaking, that of saturation at boil-ing-point with a solution of sugar, the water being afterward evaporated at a high temperature. The result is to leave the pores and interstices of the wood filled m with solid matter, and the timber vulcanised, preserved, and seasoned. The nature of moderately soft wood, it is claimed, is in this way changed to a tough and hard substance, without brittleness, and also without any tendency to split or crack. It is also rendered remarkably impervious to water. Hard wood similarly derives similar benefits. Moreover, it is claimed that the process may be completed and timber turned out ready for use in a few days." HEAT RADIATED BY THE MOON. Attempts have frequently been made to ascertain whether the moon possesses any inherent warmth, or whether the very minute heating effects are clue solely to reflected sun-heat. Professor Piazzi Smyth, Tecognising that the small caloric effects might be absorbed in the upper regions of our atmosphere, made an interesting experiment many years ago at a heigh! of 4000 ft, on Tenerilfe, from which a ready idea can be gathered of the heat given out. He found that a candle placed at a distance of 15ft from his instrument gave three times as much heat as that radiated from the full moon. It has been proved by observation during eclipses that the moon radiates heat from its surface in addition to that reflected from the sun. Professor Langjey made some very exact measurements of the lunar " heat spectrum" under such circumstances, which extraordinary observations showed that the thermal energy given out only amounted to •one-thousandth . of a degree centrigrade. But it is supposed that this small amount of heat is probably only due to the solar heat which has been absorbed. STEEL ALLOYS FOE PERMANENT MAGNETS.

A subject not well understood is that of the connection between hard steel and magnetism. We know- that steel is readily capable of being permanently magnetised, and we know that soft iron very rapidly loses such properties. Experiments have recently •been made in France on different alloys of iron with manganese, nickel, chromium, and other metals, to ascertain their magnetic properties. An alloy of 7.80 per cent, of manganese and .46 of carbon was heated to 750 degrees, and allowed to cool slowly. This was found to possess the hardness .and other characteristics of steel, except that it was incapable of permanent magnetisation. It was then plunged into liquid air and its temperature thus reduced to a very low point, which resulted in its attaining in a high degree the property of permanent magnetism. An alloy containing 25 per cent, of nickel allowed to cool from a molten state is not magnetic, and is unaffected by a magnet brought in contact with it. After being subjected to the low temperature of liquid air, however, it becomes strongly magnetic.' MAX-LIFTING KITES. ' Since Major Baden-Powell, in 1894, demonstrated the possibility of raising a man to a considerable height in the air by means of kites both he and other inventors have made numerous ascents. In Australia, America, and Russia, successful experiments have been made, and now Mr. F. S. Cody has been making demonstrations in various parts of England. At Woolwich, on March 13, lie made home very satisfactory ascents to a height of about 200 ft (although on previous occasions he is said to have been lifted as high as 1200 ft). The kites., are of rather novel design, being of the well-known Hargrave or " Box" type, with wings spread out on each side. Two or three kites are first sent up on a long wire rope, and then a much larger kite is fixed to a pulley, which is drawn, up the rope with a basket, in which the man sits, suspended from it. By means of a lever the pulley can be jambed at any desired point by the aeronaut, and by meanof a rope fastened to Ihe front of the kite the latter can be so tilted as to cause it to descend down the rope. FURNITUHE romsrc. We print below some recipes from the Druggists' Circular for preparations with which to re-polish furniture:—l. Shellac, 4 parts ; alcohol, 32 parts ; oil oi turpentine, 16 parts ; linseed oil, boiled, 32 parts ; ammonia water, 4 parts. Dissolve the shellac in the alcohol ; dissolve, in a separate vessel, the linseed oil in the turpentine and mix the two solutions, adding them slowly with continuous agitation ; then add the ammonia water and mix by agitation until thoroughly homogeneous. 2. Mix one part of old boiled linseed oil with two parts of an alcoholic solution of shellac. Agitate each time before using, and apply in small quantities, rubbing vigorously until the polish is attained. 3. White wax, 2500 parts; water, 4500 parts; potassium carbonate, 25 .parts; oil of turpentine, 4000 parts. Boil the wax in 1500 parts of the water, carrying the potassium carbonate until the wax is saponified. Add sufficient water to replace that lost by evaporation and stir still cold and add, little by little, under constant agitation, «he oil of turpentine, and continue to stir until a complete emulsion is obtained. When this occurs add the remainder (3000 parts) of the water at' at once and stir in. In case the mixture is incomplete add a little more oil of turpentine. To use the -cream-, smear a little of it on a thin soft rag and with this go over the furniture, then polish with a woollen cloth, or bi! of flannel. The cream answers equally well for leather upholstering, imitation leather, leather cloth, marble, etc. 4. Puraffine -wax, 7 ounces; petroleum jelly, 2 ounces; solution of potassa, 5 drachms; yellow wax', 3 ounces ; turpentine, 12 ounces. Place the first four ingredients in a vessel and melt I with gentle heat; allow the mixture to cool | #nd then add the turpentine, (