The Art of projection and complete magic lantern ... - Yesterday Image

77controlling the flow of compressed gas to the jets.With a single lanternit is possible to use the gas direct from the cylinder by regulating theamount of gas at the valve of the cylinder itself, this will need some littleexperience at first, but after a time it becomes much simpler, care mustbe taken not to emit more gas than the jet consumes, or the rubbertubes will be blown off. A novice should use a regulator, even for asingle jet, as it obviates all risk of this happening. The reason for notusing the gas direct from the cylinder for two or more lanterns, is thatwhen the valve of the cylinder is adjusted for the supply to one lantern,it is inadequate for two. If on the other hand, the gas be adjusted fortwo or more jets, and one jet alone is burning, the supply is so greatly inexcess of the consumption, that the tubes are blown off, or the lightitself is blown out, if the oxygen is in excess. To prevent these difficulties,a regulator is used to control the pressure, the general principlebeing that, when the flow of gas is in excess of the requirements, a smallrubber bag, situated inside the regulator is filled with the gas, whichthereby automatically closes the orifice from wherever the gas issues.There are several Regulators at present on the market :—Beards'Regulator, the Rubber Wedge shape, the Duplex and Reliable, andrecently a regulator on the principle of the first mentioned, with thedifference that the bag, instead of being rubber, is of spun metal.IFig. 38.Beard's Regulator consists of a small rubber bag of cylindricalshape, fig 38, corrugated as a bellows or camera body, C, the top of