Science and Invention

Alexandra Herald and Central Otago Gazette, Issue 505, 24 January 1906, Page 7

Science and Invention

A SQUARE foot of uncovered pipe, filled with steam at 1001b, pressure, will radiate and 1 dissipate in a year the heat obtained by the economic combustion of 3931b, of ooal, Thus, 10sg. ft. of bare pipe corresponds approximately to the waste of two tons of ooal per annum.

It is stated that a water containing 20 degrees of hardness will probably oause a 30 per oent. loss of efficiency in fuel, due to scale formation, more frequent cleaning out, and inoreased repairs, and this means an inorease of Is per 1,000 gallons in the oost of evaporation, Such a water, it is said, could be softened for 3d. per 1,000 gallons.

A PRACTICAL MOUNTING MINT. vVhon mounting wet prints of any kind, and rubbing them down with blotting paper, the blotting soon gets damp, and rubs either to a fluff or into holes. To prevent this have next the hand and along the top piece of blotting-paper a piece of tbiok highly-glazed water-proof paper, or a pieoe of thin and smooth American cloth. In either oase the hand moving along a smooth surfaoe does not have the tendenoy either to make fluff or hole 3. The blottingpaper will then last a long time. The paper may, of course, be used over and over again if dried occasionally.

A LIFE SAVER FOR SUBMARINES A Sunderland man has inveated an appliance whioh he believes to be capable of saving the lives of the crews of submarine boats in the event of a serious aooident ooourzing to those vessels. Having worked out an idea, he consulted the Sunderland borough engineer, with the tesult that they have taken out a provisional patent. The appliance consists of submarine collapsible telescope tubes and a sart of manhole. The tubes will be made of waterproof oanvas, and fitted with tings and springß, with oasing work at the top. The manhole is to be fitted to a vessel, and by means of a perfeoted devioe on the lines of the patent, it is believed that the cooupants of a submerged vessel would be able to esoape to the surfaoe of the water. NEW TYPE OF JfIOTOR BOAT. A novel type of motor-boat has been designed in France for the International Cup, to be run for Aroaohon. The hull has an absolutely flat bottom, Sft, wide in the centre of the boat. "The principal novelty, however, is the propeller shaft. No part of the latter is either inside or in oontaot with the hull itself. It is attached at the rear extremity to a bracket proIjeoting from the bottom of the keel, and the other extremity rests in a special oasing, also projeoting from the keel. In the oasing is a chain-wheel connected by a

ohain with the motor-Bhaft above. A large De Dietrich engine is employed to drive the boat. It is olaimed by the designers that by the novel shape of the hull «skin friction is reduoed to a minimum, for the vessel merely glides over the water, the propeller, shaft, its supports, and the lower part of the rudder alone being immersed.