seldom possessed of sufficient variety of knowledge to avail
themselves of every advantage arising from their position. It
appeared to me, that the importance of the results hitherto
obtained did not keep pace with the immense progress which, at the
end of the eighteenth century, had been made in several departments
of science, particularly geology, the history of the modifications
of the atmosphere, and the physiology of animals and plants. I saw
with regret, (and all scientific men have shared this feeling) that
whilst the number of accurate instruments was daily increasing, we
were still ignorant of the height of many mountains 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 conferred
just celebrity on the names of the naturalists and astronomers who
have been appointed by various governments to share 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 sciences has been subordinate to
that of geography and nautical astronomy. During a voyage of
several years, the land but seldom presents itself to the
observation of the mariner, and when, after lengthened expectation,
it is descried, he often finds it stripped of its most beautiful
productions. Sometimes, beyond a barren coast, he perceives a ridge