EDISON’S LAMP.

South Canterbury Times, Issue 2165, 25 February 1880, Page 2

EDISON’S LAMP.

The new electric lamp, on exhibition at Melno Park, Hew York, is not unworthy of the attention which it is exciting. The principle on which it is constructed is not new, for inventors have been striving to obtain a slender pencil or filament of carbon in a state of in a vacuum for more than thirty years ; but the lamp itself is as far ahead of the efforts of the earlier inventors as the modern railway car is of the ancient lumber waggon. Mr Edison has improved the Sprcngel air-pumd, and the vacant in his little glass globe is almost perfect. Only one-millionth part of the air remains. He is tints far in advance of competitors in regard to the important point of an almost perfect vacuum, on which the durability of the incandescent carbon depends. He has also been fortunate in adopting the plan of scaling up his glass globes with the blowpipe while yet attatchcd to the airpump, thus making the exclusion of the outside air complete. His paper carbons, too, arc almost as slender as hairs, possess special merits. They offer a high resistance to the passage of the electric current, and their ability to withstand a sudden shock of electricity is greater than that of carbons which have no fibre. The light of the lamps, while pure and brilliant, is moderate, being equal to that of single a fact which renders them suitable for use in dwellings. East, but least, the lamps are small and comely in appearance. The first step in the utilisation of the electric light for dwellings is the construction of a lamp. After a suitable lamp has been obtained, the next points to be considered are, liova durable is the lamp likely to be, and how costly M’ill be its use ? Unless the lamps are durable and cheap, they Avill be little more than ingenious toys. On neither of these points, hoAveA’cr, can much bo said at present respecting Mr Edison’s lamps. They have not been tested long enough. One fact, however, should not bo oi'crlookcd. Among the forty-five lamps now placed on exhibition at Menlo Park, several are already burning a little dull. What does that mean ? It is stated by MrW. E. SaAvycr, another _ inventor in the same field, that if a millionth part of air remains in the scaled glass globe the incandescent carbon must be consumed in time, and of course a A r cry delicate carbon like the paper horseshoes of Hr Edison must burn away sooner than larger ones. If Mr Sawyer is right, some of the forty-five Edison lamps ought to begin to grow dull soon, and some of them arc actually dull already. Is this a fatal weakness in the now lamp? Time is required before a positive answer can be given, but the probabilities seem to be against the groat durability of the horseshoe carbons. If the lamps do not prove durable, then Mr Edison has only partially succeeded.—“N.Y. Times.” The Xcav York “ Truth ” says that on New Year’s IWe Edison said to its reporter —avlio Avent to sec his Menlo Park illumination and wasn’t much impressed by it—that the public insisted upon visiting him, and he did not deem it polite, during the holidays at. least, to refuse them admittance. Neither does he claim that his invention is yet perfect; the present should properly be regarded as a season of experiments. At present he has not more than fifty lights burning all told ; but as fast as the carbonised paper, Avhich is at present originated by a very slow process, can be produced in any quantity, lie Avill continue from time to time enlarging the number of lights. The lights iioav in use arc kept burning night and day, and fully threc months Avill elapse before he discontinues or becomes fully satisfied Avith his present experiments.