Qazometer. ^05 



VI. 



Account of the New Gazometer of Citizen Seguin.* 



V^ylTIZEN Seguin has contrived a Gazometer, or Inftrument for meafuring the gafes, 

 which he propofcs to fubftitute to the Gazometer of Lavoijier, and of which the 

 aim is to difpenfe with the correftions required to be made for the variations of tlie 

 barometer, during the courfe of the experiment. By this new Gazometer the elaftic 

 fluid is fubjefted to an invariable preffure, by an artificial regulated preffure, fubftituted 

 iiftead of that of the atmofphere. This preffure is effefted by means of a quantity, of 

 water introduced at pieafure into the refervoirs appropriated to contain the gafes. 



The inftrument is compofed of four refervoirs. The firft performs the fame office 

 with regard to the fecond as the refervoir of a fountain lamp ; that is to fay, it obviates 

 the ncceffity of' filling it as often as would otherwife be the cafe. — .The fecond tranfmits 

 the water into the third, to produce the required degree of compreffion. — The third 

 receives one of the gafes and communicates with the fourth, in which the mixture of tlic 

 pafcs, fubjefcled to the fame degree of preffure, is made. — Each refervoir has a kind of 

 gage or level, which (hows the proportion of water and gas within. The firft refervoir 

 communicates with a bottle, which (hews the ftate of its contents. A tube or level open 

 at top, and communicating below with the fecond refervoir, (hews the height of the 

 water within. — A level communicating with a third veffel, above -a«wvell as below, that 

 is to fay, with the part filled with gas, as well as that which contains the water ; likewife 

 fliews the relative quantities occupied by the two fluids refpeftively in the veffel. A 

 cock, of which the tube communicates with the laft mentioned level, ferves to empty 

 this veffel, by fufferingthe water to flow out when gas is required to be introduced into 

 this third refervoir. — Three tubes or levels are adapted to the fourth veffel. The firft 

 placed in the middle, communicates at the fame time with the parts of this veffel which 

 refpe6tively contain gas and water. It (hews the relative proportions of water and gas 

 as they exift in the referVoir. Another tube communicating at top with the tube leading 

 from the third refervoir, and at bottom with the part occupied by water in the fourth, ' 

 fhews tlie degree of preffure exercifed by the condenfed gas upon the water of the re- 

 fervoirs, and ftands lower than the firft level. — The third tube communicates at bottom 

 with the fourth refervoir, but is open at top. It fliews the elevation to which water 

 can be raifed by the preffure exerted by the gas in the fourth veffel. It, therefore, 

 ftands higher than the firft veffel by the fame quantity as the firft ftands higher than the 

 fecond. The author calls thefe gages by the names of t*he real level, the level of pref- 

 fure, and the level of reaftion. ' 



• Communicated to tke National Inftituteof France, and abridged by Halle, in the Bulletin of the Philomath. 

 Society, No. 10, page 75. 



Vot. III. — December 1799. 3G The 



