18 



of summer. From the few observations I per- 

 sonally made, the interior of Spain forms a vast 

 plain, which, elevated three hundred toises (five 

 hundred and eighty-four metres) above the level 

 of the ocean, is covered with secondary forma- 

 tions, grit stone, gypsum, sal gem, and the calca- 

 reous stone of Jura. The climate of the Cas- 

 tiles is much colder than that of Toulon and 

 Genoa ; for it's mean temperature scarcely rises 

 to 15° of the centigrade thermometer*. 



We are astonished to find, that in the latitude 

 of Calabria, Thessaly, and Asia Minor, the 

 orange-trees do not flourish in the open airf\ 

 The central elevated plain is encircled by a low 

 and narrow zone, where the chamserops, the 

 date-tree, the sugar cane, the banana, and a 

 number of plants common to Spain and the 

 north of Africa, vegetate on several spots, with- 

 out suffering from the rigors of winter. From 

 the 36th to the 40th degrees of latitude, the me- 

 dium temperature of the year is from 17 to 



* Whenever in the course of this work, the contrary is not 

 expressly indicated, the variations of the temperature are 

 noted after the centigrade scale of the thermometer with 

 mercury; but to avoid the errors which may arise from the 

 reductions of the different scales, and the frequent suppression 

 of decimal fractions, I have printed the partial observations, 

 such as the instrument I made use of gave me. On this 

 point I have followed the plan adopted by the illustrious 

 author of the Basis of the Metrical System, M. Delambre. 



t For the note see the following page. 



