NOTES ON SCIENCE, MECHANICAL INVENTIONS, ETC.

New Zealand Herald, Volume XXIX, Issue 8986, 17 September 1892, Page 4 (Supplement)

NOTES ON SCIENCE, MECHANICAL INVENTIONS, ETC.

PHOTOGKAPHS IN COLOURS. The method adopted by Mr. Ives for photographing in colour-* is, says the British Architect, another instance of American ingenuity. Acting on Helmholtz's theory, that the nerves of the eye respond to wa\ vibrations corresponding to light of red, green, and bluish violet, and that all tints are made up of combinations of those light waves, he takes three photographs, of a scene or object, screening off from the first sensitized plate all bub the red rays, from the second all but t.he green rays, and from tho third all but the blue-violet rays. Then he places the photographs on celluloid obtained from these negatives in a three-lens lantern, and projects these so that they coincide in one picture, screening his lenses with glass of red, green, and blue-violet colour. The result is a large photograph in all the actual colours of nature, both landscapes, photographs of pictures or of flowers. A .still more striking effect is produced by placing tho celluloid positives in a kind of stereoscope lantern with prisms, when the photograph of a geranium or other flower stands out with tho vivid colours of nature. Of course Mr. Ives' results are very different from the coloured photographs often put forward as examples of actinic power, but in which all colours but one are produced mechanically. It is remarkable that M. Lippmiinn, one of the professors at the Sorbonne, has also succeeded in photographing colours. At the last meeting of the French Academy des Sciences, ho exhibited several examples of plates from coloured objects, one being taken from the national flag. EDUCATION' AND VISION. Thero is no doubt that the weakening of our power of vision is mainly duo to education. As M. Motais, of Auger, said in his paper recently read before the French Academic de Medeciue, man in hi* wild state, roaming about open country or forests, is gifted with remarkably long sight. He has to scan the horizon in the dark or under the glare of tho sun in order to espy both enemies and prey. Even. races who have partly come under the influence of civilisation, but remain in the open, such as the Arabs and the inhabitants of Northern and Asiatic Russia, possess astonishing powers of eight. They will describe a black speck on the horizon with peraecuracy to incredulous denizens of civilised Stares. Not only their comfort, but their very existence, depends on this power of distant vision. The same thing is observed with wild animals. All the larger species are remarkably long-sighted, for they, too, have to scan the distant horizon for enemies and prey, and judge distances, just like the savage man who disputes the sovereignty of tho plain and forest with them. M. Motais was anxious to discover if the restricting influences of civilisation would affect the eyesight of the larger beasts of prey. He found that tho oldest animals occasionally lost their sight alto gether owing to over confinement, but that otherwise their long sight remained. But if (he animals were caught young, ami secured in the usual cages or dens, these animals having no opportunity of exercising their powers of vision over long distances and wide expanses, grew up short-sighted. AN INOKNIOU9 CLOCK. A Brussels clocUiuakor is reported to have invented a clock which is wound up by the sun, and requires no other attention than being placed near a window into which the sun shines. A shaft exposed to tho solar rays causes an uiiderilrmight of air, which sets the fan in motion. The fan actuates mechanism which raises the weight of the clock until it reaches the top, and then puts a brake on the fan till the weight has gone down a little, when tho fan is again liberated and proceeds to act as before. As long as the sun shines frequently enough, and tho machinery does not wear out, the clock will keep going. EXKKCI.SE BETTER THAN MEDICINE. Much of tho food actually digested and assimilated is not used to the fullest extent, for want of sufficient oxidation to make it j yield the greatest amount of vitalising ] power to tho tissues of the body. .Such partially unoxidized products have an irri- ' tating effect on the organs and tissues, and : predisposes them to disease if they do not directly affect th«m with it. Exercise has a stimulating effect on all parts of tho body by inducing further oxidation in all the tissues and organs. This increased oxidation is attended by a greater demand on the part of the system for oxygen—as indicated by the greater number, force, and frequency of tho respirations. During exercise the heart beats faster, and forces more blood through tho lungs to all parts of the body, bearing in its little blood cells the precious life-giving factor, oxygen. These little cells—one constituent of which, haemoglobin, has the wonderful faculty ot quickly loading and unloading itself with oxygen— thus act as direct aids to the process of oxidation in the tissues and organs. It is the combining of oxygen with unoxidized products in the blood that gives to each' individual cell its possibility of sustaining life. Any process which increases the oxygen supplied to all parts of the body tends to strengthen the life in each individual cell, and to give it more power to resist disease. Exercise of all factor* does this most effectively, and besides actually producing in each individual cell a greater vitality, it gives a favourable opportunity for the waste products of tho tissues to be thrown off rapidly. By thus causing a further oxidizing of certain matters in the blood, it conduces in a double sense to life and health. Habitual outdoor exercise, with suitable protection from extre of weather, is the most effective means of prolonging life to old age. THE PLANET MARS. The New York correspondent, of the Standard reports some interesting discoveries concerning the planet Mars which h'tve been made through the Lick telescope. The telescope, it is said, disproves Schiapa telli's theory that the canals in Mars are double. It further discloses variability in "the polar caps, indicating the presence of snow or ice. The south cap especially shows markings resembling denuded areas, "Fons Juvcntutjs," formerly appearing single, is now seen to bo double. The southwest limb has several very bright projections, the nature of winch is unexplained. The satellites hitherto appearing as undetinablo specks of light are clearly observed, with moonlike phases in the case of the inner satellite, which was plainly seen passing into eclipse almost suddenly, as when the moon effaces a star. New and exactor element* are furnished regarding the size and orbits of the satellites. Each moves over its own diameter in about twotenths of a second, and the inner satellite revolves thrice daily round the primary planet. ROUGH Of CATERPILLARS. Edison originated electrocution on a practical scale when he waged successful warfaro on cockroaches years ago, bub his original device has been greatly improved upon and applied to prevent caterpillars from climbing up trees. Alternate wires of copper and zinc are run around the trunk of the tree at a distance of about half-an-inch apart. The casual caterpillar begins to mount the trunk of the tree, and unlimbers himself with the confidence and vigour born of an impending feast. Presently he readies tho copper wires, pokes his nose over it, and lets another kink out) of his back-bone. Half-an-inch further up his front feet strike the zinc, the circuit is completed, and the unfortunate larva is instantly a martyr to science. MISCELLANEOUS. A Glasgow paper states that an engineer resident there has, after nineteen years' labour and experimentation, devised an arrangement in an engine by which he returns all the steam back to the boiler after doing its work in the cylinder. In several cases he has got his engine installed and at work, giving most extraordinary results, and in one case in a textile factory it is doing as much work with one ton of coal as was formerly done with seven tons. A watch for the blind is among the newest inventions. A small peg is set in the middle of each figure. When the hourhand reaches a given hour the peg for that hour drops. The sightless owner, when he wants to know the time, finds which peg is down, and then counts back to twelve. Three skeletons of prehistoric men have just been exhumed in the famous caves at Mentono. They prove to have belonged to the Cro-Magnon race, characterised by dolichocephalic heads, by the rectangular form of the orbits, and by their great height. Around the necks of the skeletons were collars composed of sea shells, the vertebras of fishes, and the teeth of some animal. , ;