[ 454 



Calorific Refult. 



Heat of the Air, above 62° 

 ----- below 72,5 



2)134.5(67.2 



Mean 67,2 

 — 32. 



Fundamental Difference =: 35,2 



Compleat Height. 

 433.9>z 



+ 38.184 



rft Produfl. ■^ 

 J, 2 X ,0025 Y 



1 Firft Produfl. 

 35. 



Second Produfl, nr Logarithiiic Refult, 

 muhiplied into the firft Produfl. 

 433, qi2 ;< o.oriS 



. = 0,088 



\ 



=; 3 8, 184 fathom. 



Error. 

 2832,576 

 — 2831,3 



= . . . 1 ,276 foot in plus. 



= 472,096 fathom X 6 = 2832,576 feet. 



Sum of the Errors of both Obferrations. 

 1,276 — ,686 == 0,590 of a foot. 



These inftaaces evidently prove, that the errors of the barome- 

 trical calculation of heights proceed folely from the difficulty of 

 obtaining the true mean temperature of the atmofphere, as there 

 are hours in which the afcent of heat does not follow an arithme- 

 tical progreffion, as Pidet has fhewn, (fuppofing the inftruments 

 truly read). The propereft hours are thofe between fun-rife and 

 the hotteft hour of the day, or between that hour and fun-fet, the 

 inftruments being fhaded from the fun, and left a fufficient time, 

 (particularly the thermometers) to affume the temperature of the 



atmofphere. 



Barometrical 



