20 Meteorological Observations made in 



m 



at a knowledge of this priiiciplej and the experiments by which 



he confirmed it. In the year 1801, during a scientific excursion 



in the neighborhood of Popayan, he happened to break his ther- 

 mometer ; and in atteraptmg to mend it he was led to observe 

 the variabihty of the extremity of the scale corresponding to the 

 heat of boiling water* His reflections on this subject led him, 



after various exneriments, to the following: conclusions ; '^ The 



heat of boiling 



atm 



sure : the atmospherical pressure is in proportion to the height 

 above the level of the sea; the atmospherical pressure follows 

 the same law as the risings of the barometer, or, properly speak- 

 ing, the barometer shows nothing more than the atmospherical 

 pressure. Boiling water therefore shows it in the same manner 

 as the barometer. It can consequently show the elevation of 

 places in the same manner, and as exactly as this instrument." 

 Ensayo de una memoria sohre tin nuevo mctodo de medir las 

 montanasj etc. p. 10. His first experiment in Popayan gave b. 

 w. 75^.7 of Reaumur, the height of the barometer being 22 in. 

 111. To find then the variation corresponding to one inch of 

 the barometer : 



28'^". -22"^°. 1U=5^.1 or 61 lines. 



80^-75^.7=:4^.3. Then 



611 : 4^.3: :l2i. : — ~^— =o^,8. 



Then reversing the process 



40 3 y 12 



0^.8 : 12i.:-.4o.3 ; — ^g-=615=5UJ 



I 



Satisfied Avith this commencement, or dawning of a new theory, 



expernnents 



taking this city as the centre of his labors, and fixing the eleva- 

 tion of the barometer at 22'. Ill 2, and boiling water at 75^.65 

 of Reaumur. 



;pot 



The 



barometer stood at 21' 9^, or 14' lower than at Popayan ; the heat 



o 



was 74^.5 Reaumur. Then 



W 



Las Juntas 21 9 74^.50 



1 2.2 10.15 



