50 THE YEAR. 



nation of the mountains in Europe and America, had 

 been assigned as the limit of congelation, or above 

 which water could exist only as ice, at the equator, 

 the observed heights of those passes were pronounced 

 to be incredible. Subsequent observations showed, 

 however, not only that the measurements were tolerably 

 accurate, but that vegetation extended to a greater 

 height on the north or shady side of those mountains 

 than upon that turned to the sun ; and that a for- 

 mula which had been deduced partly from theory, and 

 partly from the facts as observed upon the Andes in 

 America, was faulty by at least a mile, or one third of the 

 whole height, when applied to Asia, in the parallel of 

 about 30 north. The occurrence of an error of such 

 magnitude, and that in the conclusions of the most 

 eminent men of very recent times, shows that the 

 greatest possible caution is required, before any thing 

 like a positive conclusion respecting the climate of a 

 country can be drawn. 



And yet the very magnitude of the discrepancy 

 which has been alluded to, is a source of encourage- 

 ment to study the natural history of the globe, not only 

 with a view of ascertaining what the facts naturally are, 

 but of finding out what ameliorations of climate may 

 be brought about by artificial means. Theory said 

 that at the place alluded to there should be frost 

 throughout the year at the height of about 1 1 ,400 

 feet above the mean level of the sea ; and experience 

 found flocks pasturing and crops ripening at the height 

 of about 16,800 feet; the cause of the difference 

 must be sought for in the surface, and if the range of 

 nature's variation be so very great, we may rest assured 



