Stem Burners.
Objection is sometimes made to the ordinary chain pulls from the fact that they jar the fixtures, and also are liable to bend the fixture branches from the strain used in operating the arm. To overcome these objections the stem style of burner is manufactured (see Fig. 12). This stem, it will be seen, carries a convenient key at the end, which is turned either right or left as in an ordinary gas-cock. The moving contact only makes contact when the gas is being turned on and lighted. When turning it off, the arm is retracted so as not to touch the fixed electrode, thus saving battery current.
Fig. 12.
Fig. 13 is a simple lighting attachment for an Argand burner. The moving lever which carries the pull has a German silver spiral spring on its top end. This strikes against the lug projecting from the circuit-wire arm and makes a spark. The lower part of the circuit-wire arm has a screw and washers for ready attachment, and is strongly and substantially made.
Fig. 13.
A means of igniting the gas from a Welsbach burner is shown in Fig. 14, and is so simple as to need no further explanation.