20 Meteorological Observations made in 



at a knowledge of this principle, 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 attempting to mend it he was led to observe 

 the variability of the extremity of the scale corresponding to the 

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

 after various experiments, to the following conclusions : " The 

 heat of boiling water is in proportion to the atmospherical pres- 

 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." 

 Ejisayo de U7ia memoi^ia sobre un 7iuevo tnetodo de medir las 

 montanas, etc. p. 10. His first experiment in Popayan gave b. 

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

 11 1. To find then the variation corresponding to one inch of 

 the barometer : '" 



28in.-22iii. 111. =50.1 or 61 lines. 



80O-75o.7=4°.3. Then 



40.3 X 13 

 Then reversing the process 



611. J 40 3;:12i. : — ^— =0°.8. 



40 3 y 10 



0^.8 : 12i.::4°.3 : -^g-=64.5=5i.4J 



Difference betwixt this result and that of the barometer 3 J lines. 

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

 he began a series of experiments in the mountains near Popayan, 

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

 tion of the barometer at 22'. 111. 2, and boiling water at 75°.65 

 of Reaumur. 



At a spot named Las Juntas I made my first observation. The 

 barometer stood at 21^ 91, or 14i lower than at Popayan ; the heat 

 of boiling water was 74^.5 Reaumur. Then 



Height of the barometer in Popayan 22' 11.2 B. W. 75°. 65 

 at Las Juntas 21 9 74°. 50 



1 2.3 1° 15 



