NOTES ON SCIENCE MECHANICAL INVENTIONS, ETC.

New Zealand Herald, Volume XXVIII, Issue 8670, 12 September 1891, Page 4 (Supplement)

NOTES ON SCIENCE MECHANICAL INVENTIONS, ETC.

FOUR CYLINDER ENGINES. Tin: introduction of the new triple expansion engines, having four cylinders, into the largo mills at Fall River has proved a success, according to the New York Sun, which in describing the engine says :— '< it is a triplo-expansion engine, with four cylinders. The steam, instead of being carried to a .single large cylinder for its | final expansion, is divided between two whoso combined capacity is such as to bear the required proportion to the intermediate. The high-pressure cylinder, with one of the low, is upon one side of the engine, and the other low pressure, with the intermediate upon the other, the cranks being set atari angle of DO degrees. This secures for the engine an equal distribution of the load between its two sides, when, as will normally bo the case, the work done in the high pressure and intermediate cylinders is equal. The cylinders are proportioned as follows : —High pressure, '20 inches in diameter; intermediate, 31 inches; and two low pressure, 30 inches each, the stroke being (50 inches' upon each side. The cylinders are steam-jacketed all over, heads* as well as barrels, and the steam passes through these jackets on the way to the cylinders. The satisfactory results of this arrangement would seem to admit of no doubt, judged by the published figures; that is, tests show that tiio engine develops its load of about 1000 horse-power upon an average consumption of 145") pounds of coal per horse-power per hour.

-'IS CULTIJKU HEREDITARY?' Professor Lester F. Wood says that the whole point at issue is'whether.' there is a cultivation of tlio mental faculties and their development ; in other words, whether the increment gained by their exercise is transmitted to posterity. Prof. Weismann and most of his followers, constituting what is now generally known as the school of NeoDarwinians, deny such transmission. If they are right, education has no value for the future of mankind, and its benefits arc confined exclusively to the generation receiving it. So far as the inculcation of knowledge is concerned, this has always been admitted to be the case, and the fact that each new individual must begin at the beginning and acquire all knowledge over again for himself is sullieiently discouraging and/ has often been deplored. But the belief, though vague, has been somewhat general that a part at least of what is gained in the direction of developing and strengthening the faculties of the mind, through their lite long exercise in special field*; is permanently preserved to the race by heredity transmission to posterity of j.he acquired increment. We have seen that all of the facts of history and of personal observation sustain t his comforting popular belief, and until the doctors of science shall cease to differ on this point and shall reduce the laws of heredity to a degree of exactness which shall amount to something more like a demonstration than the current speculations, it may perhaps be as well to continue for a time to hug the delusion. EFFECTS OF ax EXPLOSION*. The recent gunpowder explosion near Rome has excited considerable interest from the fact of some careful scientific observations which the explosion made possible. The amount of gunpowder exploded was quite large—about .10 tons, and the licet was, of course, very terrific. The magazine being located between two hills the main force of the explosion was upward, the pressure of the air quite uniform everywhere, producing some very interesting scientific phenomena. The action of the blast manifested itself in two ways—by an earthquake and by an airwave. The vibratory movement of the earth travelled with greater velocity than the air-wave ; so much so that the shock was felt in the city and suburbs several seconds before the report was heard. Flower-pots, lamps, and bottle? wore upset in closed rooms protected from any inrush of air. The blast, set the barometrical column in violent motion, beginning with a pressure of about f>")0 pounds per square meter, followed by a counter wave of suction. The first was marked by an increase of 11 millimeters in the barometer, the second by a decrease of 14 11-25 millimeters. The power of suction of this last wave was such that 1)0 per cent, of the windows were blown not inward, but outward, the fall of broken glass in the streets wounding some .'IOO passers-by. The movement in barometric column lasted GO seconds, although it is believed that onethird only of that prodigious mass of powder had time to ignite. The greater portion was blown up bodily, its explosion taking place gradually. Granules of powder were collected as far distant as Ponte Milvio. The report was heard and registered not only at Subiaco, Viterbo, and Anagni, but also at Caserti, Ischia, and I'esaro, at a distance of more than 200 miles.

AN I NY! EN'lO US COLD-I'KOnUCr.ll. t The " cryogcne," or cold-producer, of M. Cailletet (says the Globe) is constructed by M. Ducretet, of 75, Rue Claude Bernard, Paris, and is a very handy apparatus, consisting of two concentric cans of niekcllcd copper, leaving between them a narrow space. The inside can contains a spiral of copper tube, having a stop-cock at its upper end, and opening at its lower end into the space between the cans. The inner can is filled with alcohol, which serves as a bath for the spiral ; and liquid carbonic acid is allowed to ■ flow from a cylinder into tho spiral, where it expands and produces intense cold. Sponges filled with alcohol in the space between the cans absorb the gas. The cryogene. can produce a temperature of no less than TOleg, that is, 70deg centigrade, below freezing point. HtOTOfiUAI'IIS IN' natural colours. A new patented process for producing photographs in natural colours has been brought under notice by tho Art Colour Photograph Company. No claim is put forward to the production of the colours on the negative, a feat which, if not impossible, has never yet been accomplished. What the negative does is to portray the colours of the original in their proper relative gradation of tone, which is a development of the "orthoehromatic" process, as photographers term it. Having obtained the negative, tho next step is to get a print. This print is made to undergo a special treatment mechanical in its nature, by which it recoives the required colours. Only the primary colours are used, every shade and gradation of tone being secured by the negative. No artistic skill is needed to apply tho colours, but how it is done is not explained. The final step consists in the "fixing" of the prints by which the colours are rendered absolutely permanent. In proof of this claim wo were shown a reproduction of .Meissonier's " Retreat from Moscow," which we were informed was executed five years ago. The prints are made waterproof in the process, and can be mounted on paper, card, glass, opal, or other material. Besides the specimen mentioned wo liavo seen reproductions from the National Gallery and photographs of living celebrities, including one of Cardinal Manning in his robes, tins bright colour of which is wonderfully strong and refined. The process is the invention of a French photographer, M. Victor MaIhicu. The means being mechanical, the cost is but slightly in excess of the ordinary monochrome points.

MISCELLANEOUS. Asthma may bo greatly relieved by soaking blotting or tissue paper in strong saltpetre water ; dry it, then born it at night in the sleeping-room. ° Steam pipes have been mado in" England from ramie fibre. This material 13"subjected to tremendous hydraulic pressure and, having the property of being unaffected with moisture, will neither . shrink nor swell, beside being a non-conductor of heat. The pipes are said to have a tensile strength twice that of steel pipes. 0 A German biologist says that the two sides of the face are never alike. In two out of five the eyes are out of line ; one eye is stronger than the other in seven persons out of ten, and the right ear is generally higher than the left.

A new petroleum-burning boat was tried near Berlin with a 4-horse-power engine which went from six to eight miles an hour at an expense of 2 cents per horse-power per hour. The engine needs only one man to tend it, and lie can also steer. A novel method of suspending the trousers without the aid of braces is described in a recent patent. The waistband of the trousers is continued backwards on each side into two short straps, which engage with buckles. Another purpose of these extensions is to cover the openings of two pockets which can be used for valuables, &c. '