SCIENCE, MECHANICAL INVENTIONS, ETC.

New Zealand Herald, Volume XXXIX, Issue 12070, 13 September 1902, Page 5 (Supplement)

SCIENCE, MECHANICAL INVENTIONS, ETC.

THK BALLOON" A* A nFTT.CTKR OF ST» .VAIU.VES.

The French XaVal Department Lias been carrying out a series of interesting experiment with balloons for detecting submarine boats when submerged, ! in- results of which piove.l that the course of a submarine civ.:: tan lie e»-iiy followed from a. balloon in the air. The Custave Zede was used for these experiments. The boat was submerged to a depth of ten feet and more, but it was easily discovered by the seionaut when th- boat ran euuuUr to the sun's rays, although the balloon remained at a. height of 1500 ft. An ingenious telephonic apparatus was connected from (he sobmarine to "th-.- balloon, i.L order that th* hitler might signal wlif-i it hoi discovered the hoar. The experiment■-• further proved that the green colour at present employed in painting submarines is 1.0; an effective disguise, and that the ease with which submarines may in) descried beneath the surface depends on their angle with regard to the sun.

I tun iiit'Kovivc: .'.;<;: lights. I Many devices Lave hi en proposed to proi long tiie life 01 elect rie-are, lamps, The most effective arrangement consists of .1 chamber or cylindrical body around the pencil ends, winch prevents access of air, and thus secures longer life. But the use of such a. chamber is objectionable by teason of the fact that it. decreases the light ignition. While it raises the temperature of a luminous arc no means art provided j by which this increase of temperature is utilised. A German inventor believes that, I In' has devised an improvement in such an: I lamps by providing them with pencils containing an addition of metallic salts or substances 'having a higher temperature of combustion than the carbon itself. Such carbon pencils, it is claimed, will produce a highly luminous ore. The temperature of incandescence and the power of emission of light possessed by the metallic sails used will be intensified in proportion to the beau generated by the combustion of the carbon. With pure carbon pencils the reflectors are disadvantageous as regards the yield of light, by reason of (he higher temperature for reduced luminosity of the arc. With the. use of this especial carbon it is claimed that the very cause of this disadvantage is utilised in realising a distinct improvement.— Scientific American. FUti; PROOF COTTON. A valuable discovery of far-reachiug importance to the cotton-manufacturing industry has been made by Dr. W. 11. Perkins, of the Owens College, Manchester, whereby cotton and oilier similar highly - inflammable materials .-an be rendered permanently fireproof. The discovery has been achieved after two thousand experiment*. extending over many mouths. With the. exception of explosives there is no article that Hares up so quickly as cotton when it comes into contact with a light, especially in those particular goods which are made of heavy yarns mid " combed out" on both shies in order to give the appearance of flannel. The reproofing process consists of "asbestinizing' the fabric, by which means permanent immunity from bunting is assured, but the exact marine! in which ;it is achieved is not divulged. In order to ' 1 realise the full importance of the discovery: it should be understood that "asbestine fabrics'' can he washed and washed, and yet retain their non-ignitible quality. From 1 this it will be seen that the process is not that of merely putting upon the material a, chemical that for the time being renders the fabric non-inflammable, but rather that, as in the case of "mercerising," the very character of the material is changed. From the scientific point: of view much interest attaches to this feature. " Asbestinised" cloths are perfectly hygienic, and can b<? safely worn next, to Die skin. A NEW ELEMENT. Prof. Marckwald, of the Berlin University, _ announced at last meeting of the Physical Society that he had discovered a, new- element. The element in question is radio-active, and of extraordinary energy. Heir Marckwald has separated' it from radio-active bismuth. The co-called polonium, found in uranium ore, consist*!, as Hen- Marckwald discovered, substantially of ordinary bismuth and of a new metal, in the proportion of a thousand to one. The new metal can be separated by electrolytic process. The jays it emits are something like those of the metal radium, but differ in being almost completely absorbed by paper, as well as by glass. Herr Marckwald has proved that a, porcelain tube, heavily charged with electricity by rubbing, immediately lowers its charge when a morsel weighing hardly a milligramme of this metal is brought within a distance of one decimetre. The. chemical analysis of the new metal is rendered very difficult by the fact that one ton of ore* contains hardly one gramme of it. ALUMINIUM NAILS, For" years manufacturers have endeavoured to find a cheap substitute for copper, particularly for use in making nails. The American Journal of Science and Industry says:—After very numerous experiments and trials an alloy of aluminium has been found, with which nails, staples, and tacks can be made to compete with copper. Among other advantages claimed for the new material is that it is not affected by the weather and will not deteriorate. It 'is to be noticed that this quality should recommend the nails for use in laying roofs, lining tanks, etc., and also that, as the alloy is non-corrosive and non-poisonous, the new nails ought to find favour among makers of refrigerators. When the difference in point of number and weight is j taken into consideration it is Keen that aluminium nails are about four or five cents a' pound cheaper than copper nails. THERE MILLION' DYES. The nun. of artificial colouring matter* prepared since Ferkitfs discovery nearly fifty years ago of the preparation of aniline dyes from coal tar has been enormous. lb is estimated that at the present dav over ! 3,000,000 different individual dyestuff§ are easily accessible to our industries, while at least 25.000 form the subject of patent specifications. The number of colouring matters furnished by natural agencies is comparatively small,' and those that do exist threaten soon to be ignored in favoui of coai-t-ir derivatives.—Lancet. fUOTOCHAPHINO ILLUMINATION'S. At a meeting of the London and Provincial Photographic Association Mr. Sims mentioned ; curious little dodge which he had employed successfully in. the photographing of illuminations. One of the charms of an illumination is the movement produced by the flickering of die lights. 'J his is lost 111 the ordinary photograph, but Mr. Sims Sound that by gently tapping the earner'' during the exposure a movement was produced which gave the effect of glimmer in slides projected on a screen, although a difference was hardly perceptible in a print. THE MOUNT I'ELKE ERUrTION. A French observer, M. Thierry, who was within three miles of the crater on Mont Pelee on May 3, when the explosive eruption of th?. volcano occurred, has addressed a note to the French Academy of Sciences on the subject, lie states that there was no lire, nroperiy so called, nor projection of incandescent lava. It is an almost univeisal experience to find flame and fire spoken of in connection with volcanic eruptions —phenomena which are not in accordance with fact. In the convulsion of Martinique there was 110 co/nbusion, but a terrific outpouring of rock matter and deadly gases raised to incandescent temperatures. MISCELLANEOUS. A Berlin dentist has discovered that by injecting into the gums c preparation formed from fresh suprarenal capsules of oxen mid calves a total absence of pain is rendered possible as deep as the bone of the part upon which it is desired to operate. A patent ha 1 , been taken out in Germany (says the English Mechanic) for a kind of brick, made with porous concrete, saturated with tar, for building into walls in place of the ordinary wood brick, for nailing grounds and finish. A new -acetylene burner has been devised by M. Louche (says the Engineer) which not only has a much higher temperature but also the admixture of ether vapour is prevented. The ratio of the mixture is one volume of acetylene to 1.8 volumes of oxygen, and the flame, which is 6 nun. long, has a greenish dart in the centre, with a point at very high temperature. Iron and steel, it is claimed, can be easily welded without either oxidising or carburising iron.!