1844.] 



Hygrometric Tables. 



139 



given in Dr. Apjohn's " Note," I have computed the following values 

 of the co-efficient m ; viz. 



1st Series, 11 observations, .. jw = *01155 



2nd Ditto, 19 ditto, .. „ '01156 



3rd Ditto, 24 ditto, .. „ -01143 



and adopting the same method as was pursued by Professor Lloyd, re- 

 ferred to above, the most probable value of the final mean obtained by 

 combining all three of the values of m is . . . . "01150 



The same value by Anderson's tables, (see above,) .. '01145 

 The mean of which, being the co-efficient adopted, is '01147 

 Combining the means of the 1st and 3rd series, the 

 most probable value of m is .. . . . . . . '01 120 



The following table will serve to shew, that the tabular error is not 

 nearly constant within the ordinary limits of the temperature of ob- 

 servation when the computed values of the tension are carried out 

 to more than three places of decimals, and it is on this account that 

 the value of m deduced by the second series of experiments has not 

 been omitted, or rather that the final value of the co-efficient as ob- 

 tained by a combination of all three values of m has been adopted. 



Table of the Elastic Force of Aqueous Vapour, according to the expe- 

 riments of Dalton, and as computed by Biot's formula. 





Tension of Vapour. 



Computed value 







Degrees 

 Fahrenheit. 



By Dal ton's 

 Experiment. 



By Biot's 

 Formula. 



_ Experiment. 



32° 



0200 



0-19917 



— 00083 



43°25 



0297 



029582 



—-O0O18 



54°50 



0435 



043481 



— -00019 



65°75 



0630 



0-63239 



+•00239 



77 



0-910 



091001 



+ •00001 



88°25 



1290 



1-29551 



+ -00551 



99°5 



1-820 



1-82433 



+ •00433 



UO°75 



2-540 



254097 



+ -00097 



122° 



3500 



3-50003 



+ -00003 



If the numerical values in the right hand member of the equation 

 were computed as it is written, it is evident that the values of/" 



