as applied to the measurement of Heights, 341 



Table IV — July 5th, 1825. 



From this series we can hardly draw conclusions either for or 

 against the theory we propose ; the first part being favourable 

 to it, and the latter observations exhibiting the unusual con- 

 currence of the descending thermometer with descending oil. 

 We would notice the extraneous motion at Obs. 45, as being 

 certainly occasioned by the accidental contact of the person of 

 the observer with the instrument, which raising the mercury 

 0°.5, had imparted a much larger portion of caloric to the hy- 

 drogen gas, and caused the descent of the oil to a great ex- 

 tent. The temporary rise of the thermometer at Obs. 48 seems 

 to have given the turn to the oil, which becomes stationary, 

 and afterwards descends without apparent cause. It is remark- 

 able that the last three or four observations give the height 

 much more nearly than when the instrument stood for ten mi- 

 nutes together at 30.00 inches. 



Table V.— /% m, 1825. 



, NO. Stat. Hour, P.M. Therm. .^S'^''^''^'!. ^^^' ' 



56 A 6^4i(y 65.8 2978 185 — 



57 B 6.45 63.8 29.88 160 —25 



58 — 6.50 61.2 2990 158 27 



