Do It Electrically

Dominion, Volume 20, Issue 58, 2 December 1926, Page 7

Do It Electrically

Lamp With Two Separate Filaments. At the Leipsig Fair an interesting demonstration was given in the Soviet Republic display of an electric filament lamp provided with two separate filaments, each of which may be switched into circuit separately and, alternatively, the two filaments may be switched into circuit .together For the particular lamp demonstrated, when one filament alone is lighted the candle-power of the lamp is 40. The other filament lighted alone gives bO candle-power, and when both filaments are lighted together the candle-power is 100 The advantages of this, invention are that a graded illumination can be obtained economically; further, tlie life of the lamp as a single filament is greatlv increased, because when one filament’has been burnt out the other may still be used. The cost of the lamp is sure to be about 30 per cent, greater than the corresponding normal type of .filament lamp Portable Electric Clothes Washer. The latest in electric clothes washing machines, according to English advices, is an extremely simple portable arrangement weighing only 2 lib. ine appliance consists of a cylindrical casing of non-corrosive metal, to the top ot‘ which the motor casing is attached The motor is of the universal type, and is supplied for a.c. up to GO cycles or a d.c. supplv of 100 to 250 V ; consumption is 300 W Coupled to the motor shaft is a high speed turbo-pump working at about 5000 revolutions per minute, and arranged in the lower. part of the machine. The pump shaft is insulated from the motor shaft by means of a fibre coupling; and the lower-cylin-drical casing is also well insulated from the motor casing. In operation the appliance is simplv placed m an ordinary wash boiler or bath tub and clamped to the side bv the special fitting provided. On starting the motor the hot sdapv water is drawn in through a series of small holes in the lower part of the cvlindef and ejected from another orifice in a powerful jet wlucii surges through the clothes From three to 'fifteen minutes are said to be required to wash a tub full of clothes thoroughly. It is claimed for this. new washing machine that as. there ’• wear and tear on the clothes the fine, t fabrics can be washed very speedily without harm. When not required for u c e the machine can be stored away in a cupboard or hung up in tlie washhouse. The overall height is 26m. and the diameter 4in. There are few wearing parts and the bearings only require a few drops of oil about once a month. The price is £l2 12s.

Electrical Energy From the Heat of the Sea. There was a special section at the Leipzig Fair allotted to the German Institution. of Inventors, where a large

variety of new inventions was shown. From an engineering point of view, the most interesting of these was that of Dr. Brauer, which comprised a remarkable proposal for obtaining electrical energy from the large temperature difference which exists between the surface and at a reasonable depth in tropical and semi-tropical seas. This proposal was laid before the first World Power Conference at \\ emblev, but a good deal of work has been put into the development of the idea since then. , , The temperature of the surface of the sea is as high as 27deg. C. at some parts of the ocean, and may even reach a ( temperature of 30deg. C., whilst at a depth of about 200 yards a temperature of about 7deg. C. is found. Hie proposal is to provide a tube reaching to the necessarv depth in the sea, an bv means, of a propellor to cause a flow of cold water up to the sea level where tlie heat engine is stationed. By using a working substance, such as ammonia, the hot water at the surface of tlie sea can be used to produce the evaporation and the cold water the condensation of the working substance. Drawings were exhibited for a plant capable of generating from 200 to 300 horse-power the total cost of which w'as estimated a about £2500. The losses of energy corresponding to the power required for the circulation of the cold a fer are said to be about 9 per cent to 12 per cent, of the energy obtained from the heat engine. It is stated that an engine capable of developing an output of 100,000 k.w. would be a practicable undertaking.

Electrical Ore Finding. In a paper read by Professor W. Petersson before the meeting of the Iron and Steel Institute in Stockholm, it is stated that since the introduction of the electrical ore-findifig method of Daft and Williams, in 1907, ore-find-ing bv electrical means has been the subject of lively interest, and at present two Swedish ore-finding methods have been worked out. lhese have been largely used in Sweden, as well as in foreign countries, especially tn the U.S.A, and South Africa One of these methods is based on the investigation of the potential in rfn electrical field by tracing equipotential curves or measuring differences in potential between -different points-—the potential method; the other methodthe electromagnetic method—is based upon investigations of the direction and intensity of an electromagnetic field While the use of magnetic measurements is possible only for magnetite or magnetic pyrites tlie electrical methods are suitable for all kinds of deposits which have an electrical conductivity different from that of the surrounding rock—that is, for practically all ore deposits. By means of the electrical ore-finding method large deposits of copper, pyrites, zinc

and lead ores have, for instance, been detected in the north of Sweden in the neighbourhood of Skclleftea.

Miscellaneous Notes. A mammoth electric incubator in California hatches three million eggs a year.

Amongst the inventions shown at' tlie Exhibition of Inventions at the Central Hall, Westminster, was an dectric lock, invented by Mr. E. Dwyer. It is controllable from a distance and is said to be unpickable. Heriot’s (F.P.) Rugby Club has been practising by artificial light, and has obtained authority to erect electric lamps at the football ground at Goldenacre, the cost to be borne by the chib.

The revenue of tlie Toronto Electric Commissioners for 1925 was 8,827,372 dollars, compared with 726,763 dollars in 1912 (the first year of the Commissioners’ operations) and the electricity sold was 512,784,492 kwh, compared with 35,176,548 kwh. Meters in use have increased from 13,858 to 143,648 and the connections have risen from 46,296 kw to 534,182 kw.

Mr. W. J. Liberty,. Public Lighting Superintendent of the City of London, lectured on ‘‘The History of Artificial Lighting” at the Society of Engineers recently'. He stated that in about 500 miles of streets in Loudon alone there were 30,000 gas and electric lamps lighted by the local authorities, while there were 160,000 electric lamps in the tube railways. At the Cafe de Paris, London,, recently, Count Anthony de of British Brunswick. Ltd.,. demonstrated a new gramophone, which is rotated by an electric motor and has, instead of the usual sound-box, an electrical device known as a magnetic “pick-up,” which is guided over the record, converting the mechanical vibrations imparted to the needle info electrical vibrations, these being' applied to a low frequency power valve amplifier to operate a loud speaker. Piano, organ, and orchestral pieces were reproduced. One of the “Facts” given in the E.D.A. booklet on home lighting, says “The Electrician,” was:— (1) That a bedroom can be lighted for an houy for less than the cost of two hairpins. This will no doubt prompt the younger generation to ask: “Wbat is a hairpin? and no doubt the ladies will have forgotten how much a hairpin does cost. et us be up-to-date whatever happens. The following is suggested as an alternative treatment:— (2) That a bedroom can be lighted for an hour every day for 12 months for less than it costs to have the hair waved, and an electric fire used for an hour per day for a month for less than the' cost of a shampoo.