a7i(i on the Expansion of Moist Air. 431 



drawing up tlic table in question, which it 

 would be easy in mc to point out ; but I do not 

 desire so invidious a task ; more especially re- 

 specting one who has so well deserved of the 

 philosophical world ; only I would take this 

 opportunity to caution others from taking too 

 much upon credit, when they may easily sa- 

 tisfy tliemselvcs from their own experience. 



Schmidt*s apparatus, and mode of experi- 

 ment, which was my particular inquiry, come 

 next to be noticed. — The apparatus was on a 

 simple ])rinciple ; being nothing more than a 

 common barometer tube, having a bulb turned 

 up at the lower end, to whith a glass vessel 

 or two could be adapted containing water or 

 steam, and having proper istop-cocks, &c. by 

 means ofs^vhich stealm could be driven into the 

 bulb and made to expel the whole or any pan 

 of the contained air ; when this \n^ iddiie tluj 

 whole was made air-tight and immersejd iijtrt 

 water of :\T ; the condensation of the stcani 

 left the air inclosed to support such a coluinw 

 of mercury as it was able, which was i>oticetl ; 

 the whole apparatus was then im'ntersed in 

 water of any oiher temperature, and the rise 

 of the mercury indicated the expa-iision arising 

 from both air and vapour. The result of Iws 

 3d experiment on this head follows, which is 

 the one he most relies on. See page 34v3i 



