Modern magic lanterns; a guide to the ... - Yesterday Image

CHAPTEE VI.jetber, 3ncant)escent (5as, Hcet^lene, etc.The oxy-calcium light is not sufficiently powerful for thelargest displays, and a substitute for coal gas enabling themixed jet, with its intense illuminating powers, to be used,was sought for and to a great extent found in oxygen containingas much as possible of ether vapour. If oxygen gasis passed over a large surface of the volatile fluid, ether, itpicks up a quantity of that substance in the form of vapour,and when saturated vyith it the two form an inflammablebut non-explosive gas, which can be burned in place ofhydrogen ; when the oxygen only contains a fraction of therequisite amount of ether, it forms a powerful explosivemixture.The apparatus for saturating the gas with ether, or withbenzoline vapour, which has been used as a substitute, isknovm as a saturator, a general idea of the arrangement forthe use of which can be gathered from Fig. 28, in whichthe arrangement is shown very diagrammatically. Theactual designs differ from one another very considerably ;but in principle they may be regarded as constructed on thelines shown. Only one cylinder, b, and regulator, f, arerequired in such a case, the oxygen on leaving it beingtaken in two directions—in one case along the tube a to theoxygen tap of the jet, in the other along b to the saturatorc, whence it emerges by d to the hydrogen tap. One of thedifficulties earlier inventors met with was due to the rapidcooling of the ether by its evaporation, which, since theo2