INTB0DT7CTJ0N. 
XI 
ci easing, we were still ignorant of the height of many moun- 
tains and elevated plains ; of the periodical oscillations of the 
aerial ocean; of the limit of perpetual snow within the polar 
circle and on the borders of the torrid zone ; of the variable 
intensity of the magnetic forces, and of many other phenomena 
equally important. 
Maritime expeditions and circumnavigatory voyages have con- 
ferred just celebrity on the names of the naturalists and astro- 
nomers who have been appointed by various governments to 
snare the dangers of those undertakings ; but though these 
eminent men have given us precise notions of the external 
configuration of countries, of the natural history of the ocean 
and of the productions of islands and coasts, it must be admitted 
that maritime expeditions are less fitted to advance the progress 
of geology and other parts of physical science, than travels into 
the interior of a continent. The advancement of the natural 
n eU - subordiuate t0 of geography and nautical 
astronomy. During a voyage of several years, the land but 
seldom presents itself to the observation of the mariner ; and 
v. hen, alter lengthened expectation, it is descried, he often finds it 
stripped of its most beautiful productions. Sometimes, beyond 
a barren coast, ho perceives a ridge of mountains covered with 
verdure, but i„s distance forbids examination, and the view serves 
only to excite regret. 
Journeys by land are attended with considerable difficulties in 
the conveyance of instruments and collections, but these diffi- 
culties are compensated by advantages which it is unnecessary to 
enumerate. It is not by sailing along a coast that we can 
discover the direction of chains of mountains, and their geolo- 
constltutlo “> the climate of each zone, and its influence 
aild . hablts of organized beings. In proportion to 
ire toents, the greater on the surface of the soil 
d stant ti f e ,u J inl r an r d ve S etable Productions ; the more 
distant the cential chain of mountains from the sea-shore the 
ftratrthl reJf nety tL ° boSom of the earth, of those stony 
planet As S , UC . cessi011 wbicb unfolds the history of our 
particiwtvnl Z cousldered apart is impressed with a 
fmnr^innZn ^ manuer ’ we fi nd the same distinctive 
impiession in the arrangement of brute matter organized in 
mffiauiintk 80 ^! 1 ^ di f ribu . t ; ou and mutual relations of plants 
the ,. rbe .f eat . Problem of the physical description of 
fnwZlf ih’ tbc . determination of the form of these types, the 
if wn h t 1T relatlons Wltb each other, and the eternal ties which 
hnk the phenomena of life, and those of inanimate nature 
ditioZTZn ed f ? eneral ob j ect 1 had view in my expe- 
the col T } t0 S™ a sli .K bt sk etch of the whole of 
s and observations which we have accumulated, 
