122 GAS-METER. 



GAS-METER. 



BEFORE passing the purified gas to the gasometers, it is necessary that it should 

 be measured and its quantity registered, which operations are effected by the 

 Meter. Of this valuable machine there are two kinds, the Station-Meter, for 

 measuring the total products of the coal at the works before it is supplied to 

 the mains ; and the Consumer's Meter, for measuring small quantities as sup- 

 plied to individuals. 



It is of the former I now propose to speak. Its advantages are so well 

 known and so generally appreciated, that it would be superfluous to enter into 

 any lengthened enumeration of them ; I shall therefore confine myself to a 

 more practical consideration of it. 



In Plate XV. Fig. 1 is a front elevation in section ; Fig. 2 is a side eleva- 

 tion, also in section, of a station meter of the capacity of 200 cubic feet, by 

 which 300,000 cubic feet of gas may be measured and registered in twenty- 

 four hours. 



The principal part of the machine consists of a hollow drum of thin sheet- 

 iron A A, revolving upon an axis a, and divided into compartments, so ar- 

 ranged, that, as the gas enters, it shall in revolving successively fill all the 

 chambers, pass through them, and be discharged measured. 



The part of the drum which contains the gas is in the form of a concentric 

 ring, one foot six inches broad, and six feet deep, and seven feet six inches in 

 extreme diameter, which will be understood by reference to the engraving. The 

 plates which form the sides are of the same outer diameter as the drum, viz. 

 seven feet six inches, but are two feet nine inches broad ; they will therefore 

 project within the smaller diameter, leaving the centre circle (through which the 

 inlet -pipe K passes) two feet in diameter. The surface of the water contained 

 in the drum and outside tank of the meter, is four inches above the upper cir- 

 cumference of this centre circle, when the drum is in its place ; so that the 

 communication between the outside and inside of the drum is cut off by a 

 head of water of that height, and continues to be so in every part of the 



