SCIENCE NOTES.

Hokitika Guardian, 16 August 1924, Page 1

SCIENCE NOTES.

A TIDAL MOTOR. (By Science Service.) A motor for the utilisation of the power of the waves and tides lias been designed and put to the test by a Bulgarian engineer, M. VodoiiiteliarofT. who has been experimenting for JO years, and has now produced a device sutiiciently successful to enlist the support, of the Bulgarian Government, tuoording to reports received in \ ienna from. Sofia. The principle of the machine, the fifth of which the inventor has tried, is as follows:—-A stage, resting en (tiles, is run from the shore into the sett. Erom this a "receiver” or lloat. weighing about 20 tons, i.s hung by a system of chains run over reels of special construction, wltieh put into motion a series ot cog wheels. Hie receiver is fastened to the stage in such a way as to move easily in every direction according to the movement of tlie waves. Every movement of the -surface of the water produces a corresponding movement of the receiver. These irregular and chopping movements arc* transmitted by the chains and wheels into a regular movement in one and the same direction. Trials of the machine have, so reports say. been remitrkaltly successtul, and have secured the support not only of the Government ol Bulgaria, but the Chamber of Industry or the city of Burgas. Further experiments on a larger scale are to lie made. .MERCURY BOILERS.

The value of boilers using mercury vapour in the place ol steam ill (towel plants is justifying all expectations, declared Dr W. L. It. Emmet, consulting engineer ot -he General Electric Company, addressing the World Rower Conference in London. Ihe otlieieuoy of mercury vapour for developing (tower lies itt its use ot extremely high tempera! tires, without excessive pressure, and its ailantability to turbine engines. Also the heat of condensation can he used lor making steam for auxiliary power ct* for other purposes.

The continued operation of a ntereitrv boiler and turbine at the Dutch Point Station of the Hartford Electric Light Company (U.S.A.), hits suggested modifications ami improvements without developing additional ditliculties, Mr Emmet explained. Special boilers and fittings must, he used suitable to the temperatures used. Leakage of mercury and mercury poisoning aopear let he entirely avoided. Repealed nieastitT'ii'. nts of the Ittel used and the energy delivered show tt saving of ,‘)tl per cent in fuel with the mercury engine, together with other advantages of reduced space occupied and amount of water required. Mercury power is well adapted to locomotives ami boats. The studies indicate a saving of (it) (ter cent in fuel with improvements based upon the experience acquired at Hartford. The supply of mercury for the increased demand which may lollow a more genera! u-e of mercury lor power purposes does not seem to he limited. Mi* Kiiitn*! saitl. Abundant sources of mercury arc known and require only a slight rise* in price to bring it upon the market. and other sources of sitppiv w ill clotthl le.-- he revealed. RIVKIIS I'URXISI! POWER. Eight (tower projects on the navigable rivers of the I'nited Slates have keen completed since tin* American Government inaugurated its policy for the development of the navigable water-. tut.let i' s control. (. oloiicl ( hat It l * Keller, ol the United States' Army, said, in addres-iog the World Power f t■„!’(*relict* in session in London, on July I - - talcs "Science ."ervin"). Among il:e great (towel* developments upon river., in the United Stales mention d were tlm 11 mi-on R' v c*r, at Troy. New- Volk: tin* Black Warrior River, Alabama: the Mississippi River ai,.,ve Minneapolis and St. Paul : and Muscle Shoals, on the Tennessee River. Alabama, nr.i vet I'llllv developed.

AI! of these are United Slates Government operations, involving an expenditure of 50.1)1)11,00!) dollars. ’The power plant al Koekttk, lowa, is an example of successful private development, built at a cost of nearly 20,()!)(),1100 dollars. This plant produces cheap electric power and substantially benefits river trallie in that part of the Mississippi River. This development of river power is not rapid, Colonel Keller staled. The rights of navigation in early days were very carefully guarded ; later the diminishing importance of river trallie encouraged plans to develop power at the expense of the public interest. Undue encroachment was checked by Presidential veto during the administration of Theodore Roosevelt. Since the passage of the* Federal Witter Power Act in 1020, and the better adjustment of navigation and water power interest a progressive utilisation of the power resources of our navigable streams is to la* expected. Colonel Keller said. TEMPERING LAID RAI I.S. The lir-t application m Amenta of the process I'm liardei'iitg railway rails alter t!i**v have bean laid is reported from Toronto, according to the "Electric Railway Journal.” A blowpipe* is mounted on wheels, and passed over the surface of the rail al a speed that gives a temperature of 85!) degtccs centigrade In till points heated. immediately after healing a iet of water is played upon the rail, the elicit being to harden the surface and prolong it-, wearing qualities. The proofs? is cifectivc to a depth of front two to three tenths of an inch, according to the pressure used ill the blowpipe.