BRITISH FORWARD MOVEMENT.

Dunstan Times, Issue 3144, 20 November 1922, Page 2

BRITISH FORWARD MOVEMENT.

The number of materials and devices for extinguishing fire is legion, but there is quite an original touch about a new invention recently demonstrated with success by a British firm. This invention goes by the name of "fire■snow," on account of the snow-like liquid which is discharged from the nozzle when the apparatus is in operation. The extinguisher contains two liquids in a plain cylindrical vessel which, when turned upside down, causes the two liquids to mix and generate gas pressure which expels the stream of fire-snow. The material is most effective in smothering outbreaks of lire, especially those caused by oils and chemicals. The fire is kept down by the carbonic acid gas and by the thick white fire-proof coating which is formed over* the burning material.. The fire-snow is non-poisonous and may be brushed off when dry. Some of the tests were carried out on burning petrol, which is one of the most common and dangerous problehis which a fire extinguisher is designed to tackle. One. of the most remarkable of British science triumphs during the Avar lay in the production of plant which would rapidly purify large quantities of water, even of the most poisonous character. The need for such drastic measures has happily passed away, but the experience thus gained has not been lost. Indeed, during the war the process known as "chlorinntion" was applied to Loudon water, both as a war measure and as a means of conserving coal and saving money. This process, which is one of chemical purification by the aid of chlorine, avoids the. expense of pumping largo quantities of water into reservoirs for storage and partial purification. The raw river water i,s directly treated, and the success of the results can be gauged from the fact that not a single complaint as regards taste was received. In the preliminary experiments some trouble was encountered on the score of taste, but it was overcome by the use of additional chemicals. From the standpoint of purity, nothing could be better than the water thus treated; and the new process therefore is more effective as well as more economical than the old. Pull information regarding this development in pure water supply is contained in the annual reports issued by the Metropolitan Water Hoard, London, England. For reasons' well known to engineers the steam turbine, which was invented in Great Britain. was first developed in large sizes', and' it has found its) most important field in connection: with huge electric! generators of anything up to. 30,000 or 40.000 horse-poiwer. The advantages of the turbine are now being realised, however, in quite small sizes, where they aire taking the. place of the old 1 familiar reciprocating steam engine. The advantages of those small turbines are particularly felt in industries where ste'am beating is required for manufacturing processes. The steam can be exhausted from the turbine at any desired pressure and volume, quite free from oil, and therefore suitable for factory use. Tn one of the latest types of small turbine produced l in Great Britain, relatively small outputs can l>c obtained over a very wide range of speeds. A single rotating wheel iis used and very high efficiency obtained. The construction is simple and robust, and the: turbine costs less both initially and in repairs than the best steam reciprocating engine. During the last year or two there has been a remarkable development in the use of pneumatic chisels and hnminers for street work in London and other British cities. It is found that these hammers will break up concrete roads in a fraction of the time required with the manual methods. Bart of the popularity of the new system is due to the excellence of the plant devised by British engineers for the purpose. The chisels and hammers are specially designed and very handy forms of portable air compressors' have been manufcctui'cd. Recently a British company developed a form of portable compressor, especially adapted for use in hot countries. The radiator is exceptionally large, so that it may efficiently cool Hie water supply to the compressor as well as to the engine jackets The compressor is driven by a four cycle petrol engine through a special epicyclic reduction gear. This gear gives a speed ratio of 2' to I and is designed to make long contiinuous runs at full power. Every detail has been carefully arranged lo ensure endurance and quietness in running Every user of a reciprocating pump knows the endless trouble which arises in connection with the valves. However carefully those are designed and however well they are manufactured, they sooner or later require replacing or repairing owing to the heavy strain which isplaced upon them. AVith these difficulties in view countless inventors have tried to make a reciprocating pump without valves; but complete success seems to have been reserved for a British engineer. His pump has no valves and is so constructed that its cylinders (ill and discharge completely on every stroke, thus giving the highest possible efficiency. The only parts liable to repair or replacement are those employed in the driving head, and they -arc easily accessible and are standardised so that they can be rapidjy interchanged at slight cost. The materials used are specially selected to ensure the maximum of wear. During a test

recently carried out on a six-inch pump driven by a one horse-power motor, 5000 gallons of water were pumped per hour against a head of about six feet. It is a curious reflection that the earliest method! of roasting meat was in, many ways the- best. When the joint is hung on a rotated in front of a bright fire, it possesses a flavor which cannot be surpassed in any other way. Jn olden days the spits were turned either by boys or dogs, and in later years a kind of clock mechanism was used. The expense and difficulty of maintaining a bright fire had led to the discontinuance of tins method in favor of otliers more convenient but less perfect from the gastronomic point of view. By the aid oil electricity, however, w© are witnessing a return to the additional mct> 7"e A Ve J T " lUC ' h ita 1 art of the electric cooking equipment in a new British ship consisted of a cylindrical roaster in which the idea! gpnditions were reproduced' by means ol g owing electric heating element* As these heating elements give off pure radiant heat and are arranged to surround the joint, they do their work bettor than the best of former methods of roasting. . Welding by means of the electric arc is now being usod in an enormoug variety of operations in shipbuilding, boiler-making and general engineering. Une of its drawbacks is that the operator is constantly in contact with largo metal surfaces and also has to work on stagings at a height. These c.rouni.stances make even a slight shock liable to be dangerous; and in, order to ovbiate this risk a British firm of engineers has devised a very ingenious apparatus which makes it impossible tor the operator to get a shock. It is a very simple apparatus and easily portable, so that it can be carried from place to place an connected to anv welding plant which has to be used under dangerous conditions. The critical point is when the operator is changing his electrodes; and if this apparatus is used he cannot get more than 25 volts, which is so low an electrical pressure as to be perfectly safe