Magic lantern - Light in the darkness

Light in the darkness
The development of light sources for the magic lantern.

In the time between the period of candles and little oil lamps, and the period in which the use of electric light became common, all kinds of light systems were used mixed up and side by side. Usually the light system was not included in the price of the magic lanterns, so that the customer was able to choose the light source that matched his personal wishes and circumstances.	Candle The first light source ever used in the magic lantern is a simple candle, in those days made of real beeswax. Candles however were comparatively weak illuminants; also, when they burnt they became shorter and the position of the wick got lower, so the flame continual became out of optical alignment. Therefore soon the candle was replaced by the oil lamp. Later the standard 'Candle' became a measurement of light source intensity. It was originally defined as a one-sixth-pound candle of sperm wax, burning at the rate of 120 grains per hour.
		Oil lamps The first little oil lamps burned a variety of oils including vegetable oil, sperm oil, paraffin, whale oil and others. The oil lamp was one of the simplest to use. However some care was needed to position the flame at the focal point of the condenser lens, and it was also necessarily to trim the wick properly because an overlong wick produced a wobbly and unfocused light. A wick that was too short would burn poorly by a shortage of oxygen.
	Oil lamps remained frequently in use after the discovery of much better sources of light.
Three wicks oil lamp The tripartite chimney could be drawn out high to give a better draught. A flame-sight-hole at the back enables the operator to adjust the wicks with the finest accuracy whilst working.
		Limelight The limelight is a very bright gas lamp, invented in 1825 and widely used for magic lantern illumination and theatrical lighting until about 1900. It consists of a block of lime (calcium oxide) heated in an oxyhydrogen flame. The two gasses oxygen and hydrogen are fed in from outside by a pipeline system with valves. The flame from the nozzle heats the cylindrical lime block, which thereupon glows white hot. The jet is fitted with a mechanism with lever taps and cogwheel adjustment for turning and raising the lime block. This limelight produces up to 1,000 candles.
	Carbon arc lamp The biggest projection devices often used carbon arc lamps, which were employed a considerable time, also after the development of the electric light bulb. A couple of touching carbon points were connected to an electric power source. When the rods were pulled apart slightly, this produced a bright electric light, caused by the incandescent carbon particles that burned between the points. Since the carbon rods are gradually consumed, one had to adjust the rods continually to maintain the correct distance between them, and the correct position relative to the optical centre of the lantern, during the show. This difficult job was later often achieved by an automatic regulator.	Carbon Arc Burner made by Thomas Ross, London. The carbon rods are mounted on electromagnetic arms. Arc point separation is controlled by the electric current and thereafter automatically maintained at the correct separation.
Acetylene illuminant This simple and cheap illuminant was invented in 1836 by the English chemist Humphrey Davy. Acetylene gas is generated from calcium carbide, a hard greenish substance with a pungent odour. When burned with the correct amount of air, acetylene gives a pure, white light. The carbide was placed in a generator and allowed to come into contact with a controlled supply of water. Then the acetylene gas was formed that was passed to the burner through rubber tubing. Acetylene was not only popular with lanternists, but also used for illumination in locations where electric power was not available, e.g., buoys, miners' lamps, road signals and on coaches and bicycles. However the burners were never of sufficient brilliance to take the place of limelight or carbon arcs and were generally used for small-scale projection.
	Gas mantle illuminant A cylindrical fabric impregnated with a mixture of rare earths was heated in a gas flame, becoming incandescent. Also the gas mantle did not produce a sufficiently brilliant light to be generally adopted.
	The cardboard box contains a special projector lamp made by Philips, the Netherlands.	Light bulb The development of the electric incandescent lamp at the turn of the 19th century stemmed the trend toward gas lamps. Soon electricity was rapidly replacing gas for general illuminating purposes. This resulted unfortunately in the discarding of many original light sources, like little oil lamps, which were often replaced by a simple socket, mounted on a piece of wood. Also the now unnecessary chimney often disappeared. That's why nowadays collectors often find a magic lantern from which the original lamp or chimney has disappeared.
	After 1910 the lanterns were more and more manufactured exclusively for electric lighting.
	Light bulb for battery The simple toy lanterns could use a little light bulb, fed by a weak, and therefore children-safe current. This lamp has a built-in flat 4.5 V battery as also used in flashlights. Some toy lanterns had a built-in socket for such a small bulb in the back.