xxii 



circum-meridian altitudes of the moon, to 

 determine the longitude by the differences of 

 the declination ; researches on the relative 

 intensity of the light of the austral stars ; 

 geodesical measures, &c. Secondly, a trea- 

 tise on the astronomical refractions under 

 the torrid zone, considered as the effect of 

 the decrement of caloric in the strata of the 

 air ; thirdly, the barometric measurement 

 of the Cordillera of the Andes, of Mexico, of 

 the province of Venezuela, of the kingdom 

 of Quito, and of New Grenada ; followed by 

 geological observations, and containing the 

 indication of four hundred and fifty-three 

 heights, calculated, according to the me- 

 thod of Mr. Laplace, and the new co- 

 efficient of Mr. Ramond ; fourthly, a table 

 of near seven hundred geographical posi- 

 tions on the New Continent ; two hundred 

 and thirty-five of which have been deter- 

 mined by my own observations, according 

 to the three coordinates of longitude, lati- 

 tude, and height. 



II. Equinoctial plants collected in Mexico, 

 in the Isle of Cuba, in the provinces of Ca- 

 raccas, Cumana, and Barcelona, on the 

 Andes of New Grenada, Quito, and Peru, 



