NOTES ON SCIENCE MECHANICAL INVENTIONS, ETC.

New Zealand Herald, Volume XXX, Issue 9307, 16 September 1893, Page 4 (Supplement)

NOTES ON SCIENCE MECHANICAL INVENTIONS, ETC.

DEEP SEA LIFE. Tub early belief in the barrenness of the deep sea was based upon" the assumption chat these groat depths were not penetrated by sunlight, not even by the faintest glimmer of light, and that the pressure of the overlying water was immense. These assumptions were correct, possibly with the exception of the belief that not even a gleam of light penetrated to the ocean bottom. As for the effect of the pressure, the fact was strangely overlooked that pressure is not ail obstacle to living, provided that the pressure is distributed throughout the body. There is a pressure of 151b to the square inch on every part of our body, but since this pressure is applied to all side* and to every molecule of the body from all directions, its effect is neutralised, and we are not aware of its presence. It is just so with the denizens of the deep. They swim about with as much ease as their relatives upon the ocean's surface, notwithstanding that there is pressing upon them a weight of many tons to every square inch. Remove them from their homo and raise them to the surface, and they experience tho same result that an aeronaut experiences when he asconds to the upper strata of the atmosphere, except, that it is a vastly more powerful effect. This is why deep sea fishes come to the surface with their eyes protruded from their heads, their air bladders extending from their mouths, and even their skin broken open. OPERATION OF THE ELECTRIC MOTOR. The system of electric-car locomotion consists of: — (a) A dynamo or generator in which the armature is forced to revolve so that its loops will cut the lines of force proceeding from an electro-magnet, thus generating a current of electricity, and (b) a motor, in which the revolving loops of the armature are attracted to the pole of an electro-magnet, through whose coils the above current is made to pass, thus forcing the armature when properly geared to turn the car-axles'. The current is conducted from the armature of the dynamo or generator located in the power-house to the overhead wire, thence through the trolley of the car to bo propelled to tho field of the motor, and also to its armature, which is geared to the car-axle, thence through the wheels to tho rails on which the car runs, and so back to the power-house, thus completing the circuit. It is the office of the motormnn to break this current when he wishes to stop the car, or to complete it when he desires to proceed ; in other words, to turn the current on or off at will. A PAVER TO PREVENT FORGED DOCUMENTS. It is very desirable that dishonest persons be prevented from duplicating certificates of stock, bonds, drafts, and such valuable documents ; and many devices have been employed for this purpose. A new process has just been introduced for making a paper which will at least bo difficult to imitate successfully. Ink is applied to a lithographic stone, and another siniiliar stone is placed on its face and the two rnbberl together until the ink is so distributed that a variegated design is produced. When tho ink is dry the design is transferred to paper after the usual manner in lithographic printing. Of course any colour may be selected for the ink. It is manifest, also, that the design thus cheaply produced can be varied indefinitely until a pleasing or effective one is obtained. A counterfeit is detected at once when compared with a sample ot the genuine paper. MIND-READING It now does not seem improbable that, when by the power of thought an imago is evoked, a distinct reflex action, 110 matter how weak, is exerted upon certain ends of the visual nerves, and therefore upon the retina. Will it ever be within human power to analyse the condition of the retina when disturbed by thought or reflex action, by tho help of some optical or other means of such sensitiveness that a clear idea ot its state might be gained at any time? If this were possible, then the problem of reading one's thoughts with precision, like tho characters of an open book, might be much easier to solve than many problems belonging to the domain of positive physical science in tho solution of which many, if not tho majority, of scientific men implicitly believe.Electric World. THE SEVEN WONDERS OK COREA. A Chinese paper describes tho seven wonder* which Corea, like unto other Oriental countries, possesses, and which played a conspicuous role in antiquity. The Corean " wonders " consist, first, of a hot mineral spring near Kin Shantao, which is capable of curing sickness and diseases of all sorts. The second wonder is tho two wells, one at each end of the peninsula, which have the peculiar characteristic that when one is full the other is empty. The water of the one is intensely bitter, that of the other has a pleasant and sweet taste. The third wonder is a cold cave from which there issues constantly an ice-cold wind, with such force that a strong man is unable to stand up at'ainst it. A pine forest which cannot be eradicated constitutes the fourth wonder. No matter what injury may be done to the roots, the young trees spring up again like the pluenix from its ashes, The most remarkable, however, is tho fifth wonder—the famous hovering stone which stands, or rather appears to stand, in front of a palace erected to its honour. This is a massive rectangular block, free on all sides. Two men standing, one at each end, can draw a cord underneath tho stone from side to side without encountering any obstacle. Tho sixth wonder is a hot stone which has been lying from time immemorial on the summit of a hill and evolving a glowing heat. The seventh Corean wonder is a sweating Buddha. This is guarded in a great temple, in whose court, for thirty yards on all sides, not a single blade of grass grows. No tree, no flower will flourish on the sacred spot, and even wild creatures are careful not to profane it.

TUB HIGH ATMOSPHERE. Beyond 29,000 above the sea level, the height reached by Glaisher in 1862, man has never been able to navigate the air. Various problems concerning the region farther awaysuch as the temperature, the pressure, the quantity of moisture, the composition of the air, etc. —have attracted the attention of physicists, and have at last led to the experiments of M. Hermite, who, during the last few monts, has been sending up pilot balloons, carrying registering apparatus. These balloons are very light, with a capacity of about 100 to 200 cubic feet. Falling at a distance from Paris, ranging up to 200 miles, the balloons have nearly all been returned by their finders, as requested on a card attached to each, and one has brought down records from a height of 30,000 feet. Tho instruments used are very light and simple. With larger balloons and systematic exploration, it is hoped that the secrets of the air up to at least 40,000 feet may bo made as familiar to us as those of the deepest and darkest depths of the sea are gradually becoming. SNAKES AND WILD ANIMALS IN INDIA. The destruction of human life by wild animals and snakes in India varies somewhat from year to year, but is always considerable. In 1891 more human beings were killed by wild beasts and snakes than in 1890,' the deaths being respectively 24,300 and 23,801, of which by far tho largest proportion—more than 21,000 in each case —were due to snakes. Cattle also suffered largely, but wild beasts are more fatal'to them than snakes. The number of human deaths is small relatively to the population of India (1 in 74,697 for wild beasts, and 1 in 10,166 for snakes); but, small as ib is, it deserves the serious consideration which it is receiving from the Indian Government. REFUSE AND ITS USES. In Paris nothing is wasted, not the smallest scrap of paper—that which everyone also throws away here becomes a source of profit. Old provision tins, for instance, are full of money. The lead soldering is removed and melted down into cakes, while the tin goes to make children's toys. Old boots, however bad, always contain in the arch of the foot at least one sound piece that will serve again, and generally there are two or three others in the sole, the heel, and at the back. Scraps of paper go to the cardboard factory, orange peel to the marmalade maker, and so on. The ideas suggested are not always agreeable, and bo see a ragpicker fishing orange peel out of the basket is enough to make one forswear marmalade, but there is worse than that. The most valuable refuse—that which fetches 2 francs the kilois hair; the long goes to the hairdresser, while the shorb is used, I among other things, for clarifying oils,