GAS-LIGHT.

115

**°le suj so situated on the box C, that whatever ht the size of the jet, a fixed tem-perature is given t6 the box, that temperature depending on the quantity of flame in

64 63

htact with the box, and not at all on the length of the jet. The jet being lighted,t a the box C thereby heated, the gas which passes through it is raised to the same^Perature, and, flowing out at the tube c, impinges on the glass cylinder whichi a PPens for the time to be lowest; the heated gas soon raises a vapor in the^ ' Ve r cylinder, the expansion of which drives the liquid into the upper one, until itl l ? c °mes heavier than the counterpoise/, when the cylinders swing on their centre, the‘‘§her one descends, and comes in the line of the current of hot gas, and the lower onet l® Ce nds; the same motion continues as long as the jet a burns. The same effect oncylinder is maintained, however the outward temperature may change, by thec gas, which, issuing from the curved side of the hood EE, impinges on the upper'Pder, and hastens the condensation of the vapor which it contains.e V e cold S as an(1 the heater vary in temperature with the room, and thus counteractTi.oth.er- . . .

.he lighting of the jet a is essential to the action of the meters; in order to insure

■pL S > the supply of gas to the burners is made to depend on it in the following manner.0)1 e Pipe G, by which the gas leaves the meter, is covered by a slide valve, which isw?* e d and shut by the action of the pyrometer g; the pyrometer is in communicationto. h and receives heat from the jet, and opens the valve when hot, closing it again

H x he speed at which the cylinders vibrate is an index of the quantity of heat com-ti lr ' llca ted to them, and is in exact proportion to the quantity of gas blowing on them.$h§h the pipe c and curved side of the hoods EE. .

hi le gas passed through the heater is a fixed proportion of the whole gas passing thec n „ er i therefore the number of vibrations of the cylinders is in proportion to the gas

haumed.

tcf tn «n of wheel-work, with dials similar to that used in the common meter, regis-| ^e vibrations.

^“hplicity, accuracy, and compactness, are the most remarkable features of this“ament, and the absence of all corrosive agents will insure its durability.