GAS.— Consumers’ Meters.

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water, and the outlet, c, is just coming to the surfaceof the water. The outlet, c, having risen above thesurface, the gas will escape into the upper portion ofthe outer case. As the gas passes out of a compart-ment in the situation of c, by the outlet, c, waterwill enter by the inlet, b ; and as the drum revolvesthe compartment D having occupied the position inspace of C and B, comes into the position A, when itis entirely emptied of gas and filled with water, until,by further revolution of the drum, the compartmenthaving come again into the position of d begins tofill with gas, as already described. That which hasbeen described for one compartment takes place forthe other three, and it will be seen that there willalways be two compartments discharging their gasinto the outer case above the water level, one com-partment filling with gas, and as it fills causing theinner drum to revolve, and one compartment full ofwater. The motive power, causing the inner drumto revolve, is the pressure of the gas in the mains, astransmitted from the gas holder at the gas works,and the quantity, of gas will be ascertained from thenumber of compartments which have been filled andemptied, that is, from the number of revolutions ofthe inner drum, which are registered by a train ofwheel work and a dial plate in the usual manner.The gas so measured and passed through the meteris conveyed to the burners by a pipe communicating inany convenient manner with the outer case, and theaction of the meter is suspended when the gas doesnot pass away. The way in which the gas enters the

measuring compart-ments of the innerdrum will be betterunderstood by refer-ence to Fig. 22, whereb and e are the ex-tremities of a shortpipe, by which the gaspasses into the drumof the meter and fillsthe compartment c,which is in connectionwith the measuringchambers. The man-ner in which therevolutions of thedrum are made toaffect the train ofwheelwork, which indi-cates the amount ofgas consumed, is shown in Fig. 23. The spiral worm,u, is fixed on to the axis of the drum, and works into

Fig. 22.

Fig. 23.

a wheel, the spindle of which passes through a tubewhich is sealed by dipping under the water containedin the case.

The dry meter is so called inasmuch as its workof measurement is accomplished without the agencyof water, the measuring chambers being of metaland leather, so combined as to open and shutvery much in the same way as a bellows. The

Fig. 24.

construction of Glover’s meter is shown inFigs. 24 and 25. The diaphragms, as themeasuring chambers are termed, are two in num-ber, and arranged base to base. The admission

f Fig. 25.

and exit of the gas is so regulated by suitablevalves that the expansion and contraction of thediaphragms is alternate, and the passage of gas isthus as it were continuous. The movements of thediaphgrams are communicated by means of levers to