THE ELECTRIC LIGHT IN THE LONDON POST OFFICE.

Marlborough Express, Volume XVII, Issue 299, 22 December 1882, Page 2

THE ELECTRIC LIGHT IN THE LONDON POST OFFICE.

Tiieke was an important installation of the Edison electric light m the Press Department of the Telegraph Office, St. Mavtin's-le-Grand, and the work thuß carried out solves what have hitherto been considered some difficult problems m the question of electriclighting. The first interesting fact is that the lighting is part of a "system" supplied at a distance from the place lighted, the Edison Electric Light Company having its centre on Holborn Viaduct. The extension to the top room of the General Post Office is the greatest yet made from one centre, the distance from the dynamo-room of the company's office to the "press-room" of the General Post Office being 1,950 ft. The importance of the work thus accomplished is obviouß. The company claim that they can work m circles of half a mile radius, and the radii from Holborn Viaduct will include St. Paul's and the district around it, Blackfriars, pare of Fleetatreet, an important part of Holborn, including the Circus, the Meat Market, and the whole of Smithfield. The "press-room" to which the Edison electric light has thus been supplied is a very busy part of the Telegraph Department (1,200 persons being employed there), which occupies the whole upper floor of the western building m St. Martin's-le-Grand. The buildings, m fact, are hives of industry night and day. The Post Office authorities have long been alive to the necessity of replacing gas by electricity, and have tried more than one socalled "system." The proved danger of fire from one, and inconveniences arising from the necessity of having a special engine m another, with other practical difficulties proved m the working, led to their discontinuance. Under the advice of Mr Preece, the electrical engineer of the Post Office, the Edison system was attached. The first lighting was soon after eight o'clock, and when the gas m the " press-room" was extinguished a turn of the switch lighted up fifty-nine incandescent lamps of the well-known pear-shaped pattern, with the carbon of the shape of an elongated horseshoe. The effect of the change waß very marked. In the telegraph room the atmosphere was henry and heated. In the room lighted by the Edison lamps an even light without any shadow was thrown over all the tables, while the atmosphere, previously heated by gas, sensibly diminished even m the short space of about twenty minutes. It was shewn that the lamp itself was perfectly free from danijer, lamps being removed while burning, and replaced by others. Each separate lamp, it was shown, could bo turned on and off independently of the others, and all could be switched off from the main. The electricity is worked from low pressure, minimising danger from contact with tho wires, and a safety plug of fusible lead at each lamp and at each junction has been ingeniously devised as a means of checking accident from any increase of current, as the lead, with any increase of heat, would melt, and thus extinguish the lamp harmlessly. The work of preparing the " press-room" of the Post Office for the electric light was carried out m about ton days.