Science Notes.

New Zealand Mail, Issue 1030, 27 November 1891, Page 6

Science Notes.

The Royal Society of London has appropriately awarded the newly founded Darwin medal, given for the first time this year, to Dr Alfred R. Wallace, for his independent origination of the theory of the origin of species by natural selection.

It is proposed making engines of aluminium to develop 34-horse power, and to be used for directing the movements of a French war balloon of 3000 cubic meters capacity, experiments with which are to be made in April next.

The method of treating wine by electric’ ity, devised recently in France, destroys the fermentation. It is thought that light wines that cannot be exported, owing to being ruined by the process of fermentation, can by this process be sent abroad without danger.

Rear-Admiral Belknap, of the United States Navy, combining his discovery of the greatest oceauic depths yet found in the Japanese Kuro Siwo with what other explorers have found in different oceans, announces the conclusion that, ‘as a rule, the deepest water is found,- not in the central parts of the great oceans, but near, or approximately near, the land, whether of continental mass of island isolation.

What is said to be the largest and most powerful wheel in the world is that in operation at. the Burden Iron Co.’s plant at Troy, N.Y. It was constructed in 1851 by the late Henry Burden, and is an overshot wheel of 1200 h.p., 60ft in diameter, 22ft. in width, and containing 36 buckets, each 6ft. deep, and is so practically constructed as to be readily controlled by a lever, which gives it any degree of power required.

It is stated that a locomotive is being built in Milwaukee, Wisconsin, having ten wheels, three of which on each side rest upon the rails and are surmounted by two others, the tires of which have frictional contact with the tires «f the wheels below. Then, surmounting these two wheels is the driving-wheel of the locomotive, the wheel arrangement on each side being that of a pyramid, with the driving-wheel on top. As the lower sets of wheels are of much smaller diameter than the driving-wheels which transit motion to them, it is claimed that the ordinary speed of a locomotive can be doubled by the use of this gearing.

A curious and interesting calculation has been made by Professor Rogers, of Washington, on the dynamite power of coal. According to the professor, a single pound of good steam coal has within it dynamatic power equivalent to the work of one man for one day. Three tons of the same coal represent a man’s labour for tie period of twenty years, and one square mile of a seam of coal, having a depth of four feet only, represents as much work a 3 one million men can perform in twenty years. Such calculations as the above serve to remind us how very wasteful our methods of burning fuel are, in spite of the efforts of inventors in the direction of economy.— Iron.

What is a flash of lightning 1 asks a correspondent of the English Mechanic. Cannot any of our professors give us a true definition of this simple query ! Of course, everyone knows that it is caused by an electric current passing between the earth and the clouds, or perhaps an interchange of currants, vibratory if you will. That the flash is caused by tha burning of the air and its contents as the current passes j seems probable, and during the craze about dark flashes having been found on the photographs of lightning, one of our most learned professors propounded the idea that they were occasioned by the burning of the air in the path of the flash, thereby producing a gas of a different refractive power from the air. This view would lead to what we may suppose to bo a fact—that the air and its contents are really consumed by the current as it passes, for we know that a flash of the same character does not take place in a vacuum where there is nothing to consume.

Yet another mode of marine propulsion has been patented, which is to revolutionise the present methods of steaming. The apparatus consists of two endless chains, to which paddles are fixed, revolving on large drums placed at the stem and stern of the vessel. The paddles enter the water over the stain drum, feather-edged, and pass along the keel to the stern. On coming out of the water they return to the stem through a special chamber in a horizontal position. The paddles work beneath tha vessel in a double keel. The chains will be driven by horizontal engines placed at the s orn. It is modestly claimed that by the adoption of this new system of propulsion tha speed of vessels will be increased to 30 and 40 knots an hour., and also that this increase of speed will he accompanied y a reduction of 50 per cent in the cost ®t the fuel.