396 



Intelligence and Miscellaneous Articles. 



perature between the two cylinders, which forms the basis of the 

 principle on which the vibrations are kept up. The " working gas," 

 after acting on the lower cylinder, as above described, flows down 

 through the main body of the meter, and along the outlet at the bot- 

 tom, where it re-unites with the " neutral gas" coming through the 

 regulating disc Z, and with it passes to the general exit, K, towards 

 the burners. 



This, then, is the description of the whole of the mere meter, 

 and it will be evident that no alteration in the measure can, at any 

 time, take place by the leakage of valves, there not being any in, the 

 working parts, neither is there therein any membrane or partition, 

 that when such become acted upon, and rendered porous by the ac- 

 tion of the gas, any portion can escape through them unmeasured ; 

 the moving power being the small light at the top (the " meter jet"), 

 it will likewise be apparent that there is not the least resistance to 

 the flows of the gas, and that thus the gas passes through every part of 

 the meter in the same uninterrupted way it would flow through a 

 pipe, neither interfering with the perfect steadiness of the lights, nor 

 requiring any pressure. 



The remaining mechanical contrivances are for stopping-off the 

 gas from the burners when the meter jet is not lighted, for giving 

 a temporary extra temperature to the heater, for a few minutes only, 

 when the meter jet is first lighted, and for the regulation of that 

 jet (when the meter is originally fixed in its place) according to the 

 pressure ; the whole contrivances being chiefly, as before observed, 

 for preventing fraud, and ensuring proper registration. 



To prevent the gas flowing to the burners, except when the meter 

 jet is lighted, and the meter registering accordingly, a valve which 

 communicates with the supply of gas is opened or shut by the ex- 

 pansion or contraction of a pyrometer, the heat to which is com- 

 municated by the small jet at Gr. 



Fig. 1. — Front elevation, with the Fig. 2» — Section from the front to 



case of the meter removed. the back of the meter. 



