LIGHTS OF LONDON

Evening Post, Volume CXX, Issue 126, 23 November 1935, Page 12

LIGHTS OF LONDON

A BLAZE OF COLOUR

SHOPS AND THEATRES

NEON TUBE INDUSTRY

(From "The Post's" Representative.) LONDON,'November 2. It is a long time since "Punch" came out with the story of the country niece gazing in rapture at the Piccadilly Circus sky signs. "Don't look at those beastly things," said the ..London uncle. "It only encourages them." Even before the war these advertisement sky signs had come into fashion. There were not many of them,; however. They had got as far as Sydney, for in 1913 or 1914 a simple New Zealander entering Sydney Harbour for the first time in the darkness was surprised and delighted to see an. aeroplane outlined by coloured lights over the harbour. Among other things, it proclaimed the excellence of a certain well-known whisky. The war came and London lights were dimmed; the streets at nights were dismal. The tops of the lamps were painted black so that the rays were cast downward, and half the lamps were not lighted. No. gleam of light was allowed to issue from the windows of the houses. If by accident or carelessness a light was visible the police would immediately pay the occupant of the residence a visit. Then with the Armistice the lights flashed out again and the polished streets once more reflected the gay illuminations. Ever since then the lights of London have been growing in intensity and numbers, until today the main streets of the West End as soon as darkness falls are a flood of blazing colour. It is the reign of the neon light. A French invention, the patent has expired in Great Britain, and there is no restriction to the manufacture of neon tubes. IN THE FACTORY. Of so-called neon lights there are red, blue, and green. The blue colour, however, is obtained from a tube filled with mercury vapour. The green colour is also obtained from a mercury vapour tube. The glass of the tube is coloured amber which blocks the blue light, but allows green to penetrate through. The light seen in a neon-filled tube is red, but the red can be varied by colouring the tube. A large manufacturer of these tubes permitted the writer to look over his -factory. It was interesting to see the tube bending. Printed designs or figure designs lay before the glass blowers, and they scrupulously bent their glass tubes according to pattern. When the tubes were the required shape a quarter-inch tube was blown into .the neon tube towards one end. The ends of the neon tube were closed With the electric poles, and the shaped tube was conveyed to the pump. The quar-ter-inch tube was blown on to another glass tube attached to the pump, and the process of exhausting the air from the neon tube was begun. Through another narrow tube at the other end the small amount of neon gas was allowed to. enter. The electric current was turned on and the tube was lighted up to help in the expulsion of the remaining air. When a satisfactory exhaustion of air and replacement of gas was accomplished, the two narrow tubes were blown and sealed. ; In the case of the blue lights a drop of liquid mercury^ was to be seen in a bulb of one of the small attached tubes. As the air became exhausted the mercury gradually vapourised i*id filled the interior, in due course being sealed within the tube. A recent development is the use of helium gas, which gives a gold-coloured light. IN CASE OF FIRE. Each neon installation has to have its own transformer to convert the ordinary alternating current from the main to 4000 volts or higher. The current is very small, but very dangerous. In the case,of a fire,-if the 4000-volt current should come in contact with a jet from a hose the current would travel down the jet of water to the fireman. Hence, provision has to be made to turn off the current from the outside of a building in the case" of a fire. . Every building with a neon sign in operation, therefore, has a switch on the outside wall eight feet from the ground. . . .-...■' Tube lamps are now becoming very popular. These are made of threeply opal glass with the white glass in the middle of the ply. The advantage of these tube lamps is that the ordinary electric current may be used along an interior filament. They are consequently not so dangerous as the neon lights, but they cannot be twisted and bent into designs so readily as a neon tube. The filament is insulated by glass held in the centre of the tube, by means of thin metal arranged like the spokes of a wheel. All modern architectural designs of public buildings involve the use of these tube lamps, which are up to 4ft in length. The tubes are m a variety of colours, such as yellow, blue, green, pink, red, and amber. They can be bent into a circle, for instance, to make a "C," but a letter like "F" would have to be made up of three distinct lamps. There are certain restrictions on the installation of neon signs along the main thoroughfares. For instance, they must not be too near to traffic signal lights. It would appear, however, that the competition today is keen. Retailers vie with one another to attract the public eye after dark. Theatres must spend a fabulous sum in advertising plays on the front of their buildings. Practically every important theatre is a blaze of lights. A ride on the top of a bus after dark along the Strand, Piccadilly, Regent Street, or the long length of Oxford Street, is a procession through a luminous flood of red, blue, and green. With so. many signs it is questionable whether one notices any particular one, but at least they brighten life, and doubtless give extra work to the Coalminer, to the .power stations, to the electricians, and a host of other workers.