759 



menon be general * in Europe, it remains to be 



9 Some observations made in Europe in the hollows and 

 on the declivity of mountains, and the supposition of the dis- 

 placing of the air in the layers superposed on each other, 

 have led some naturalists to believe that the maxima and 

 the minima could not coincide at la Guayra and Caraccas ; 

 on the coast of the South Sea (for instance at Payta), and 

 at Popayan, or Santa Fe de Bogota ; at Vera Cruz and at 

 Mexico on the coast of Malabar, where M. Horsburgh ob- 

 served, and on the plains of the Mysore and of Nepaul. 

 The preceding tables prove that these doubts are altogether 

 unfounded with regard to the table-lands situated between 

 the tropics. The observations of M. Ramond, made at the 

 height of 210 toises, at Clermont-Ferrand, give us a right to 

 suppose from analogy, that in the elevated plains of La 

 JVJancha, in Spain, at 320 toises, we should see the barome- 

 ter ascend at the same hours as at Valencia or Cadiz. We 

 have already mentioned, that the observations at Saint Ber- 

 nard and Geneva, were made at two periods of the day the 

 least fitted to shew us the oscillations of the mercury, at 

 the variable hour of sun-rise, and the fixed hour of two in 

 the afternoon. These periods precede unequally the maxima 

 and the minima. In the observations at Geneva the barome- 

 ter is at sunrise, in winter as in summer, a little higher than 

 at two in the afternoon j but at Saint Bernard, during the 

 twelve months of the year 1824, the mean of sunrise was 

 five times lower (January, April, June, August, October,) 

 three times higher (February, May, July), and four times 

 equal to the mean of two in the afternoon. (Bouguer } Fig. 

 de la Terre, p. 39. Deluc. Rech. sur les Modif. de V Atm. 3 § 

 528, 530, and 59ti. BibL Univ. pour 1820. Juillet, p. 190, 

 Tom. x, p. 20. Daubuisson, dans le Journ. de Phys., Tom. 

 lxxi, p. 24). In the rapid lowering of the barometer on the 

 22d of February, 1823, the maximum of the descent took 



