The Injector Jet.—This is essentially a mixed jet, and in outward appearance differs but little from one of the ordinary type (Fig. 20), but is so constructed that the pressure of oxygen 'sucks' coal gas into the mixing chamber, and so obviates all necessity for the latter being under pressure.
With this jet there is little or no danger of the jet 'snapping' out through a surplus of oxygen, as the greater the flow of this gas, the greater the suction on the coal gas side.
The light is not quite equal to a good mixed jet, but very nearly so, and therefore this jet is deservedly gaining in favour every day.
One point must be noted: the oxygen itself must be under greater pressure than with the ordinary mixed jet if the best light is to be obtained, and therefore a special regulator must be used, or one of ordinary type modified (which can easily be done by the maker), and rubber connections must be securely tied both on to jet and regulator, as the pressure required to work this jet to advantage, while not enough to burst a rubber tube, is enough to blow it off an easy fitting connection.
The Oxyether Light.—This is practically similar to the oxyhydrogen, except that ether vapour is used in place of the hydrogen or coal gas. The method adopted consists essentially of passing a stream of oxygen through a vessel packed with some porous material (such as cotton wool or cotton gauze) which is saturated with ether. The oxygen
becomes saturated with ether vapour, and the mixture is then used in place of the coal gas supply in a double-pressure jet, an additional supply of free oxygen being still required through the ordinary oxygen tap.
The arrangement is cheap, as it dispenses with the necessity for a coal gas cylinder, and effective, as the light is little, if at all inferior to the oxyhydrogen, but differs from the latter in this, that with careless handling an accident is possible.
In competent hands there is no danger, and I have used ether saturators myself scores of times without one single contretemps; but it should not be entrusted to any chance amateur.