continent, must be very near three thousand miles from S.E. to N.W. In
such a vast extent of mountains, the perpendicular height and width of
base must necessarily be very unequal. We were about eight days in
crossing them; whence I conclude, from our daily rate of travel, that
they may have, at this point, i.e., about latitude 54 deg., a base of two
hundred miles.

The geographer Pinkerton is assuredly mistaken, when he gives these
mountains an elevation of but three thousand feet above the level of the
sea; from my own observations I would not hesitate to give them six
thousand; we attained, in crossing them, an elevation probably of
fifteen hundred feet above the valleys, and were not, perhaps, nearer
than half way of their total height, while the valleys themselves must
be considerably elevated above the level of the Pacific, considering the
prodigious number of rapids and falls which are met in the Columbia,
from the first falls to Canoe river. Be that as it may, if these
mountains yield to the Andes in elevation and extent, they very much
surpass in both respects the Apalachian chain, regarded until recently
as the principal mountains of North America: they give rise,
accordingly, to an infinity of streams, and to the greatest rivers of
the continent.[AF]

[Footnote AF: This is interesting, as the rough calculation of an
unscientific traveller, unprovided with instruments, and at that date.
The real height of the Rocky Mountains, as now ascertained, averages
twelve thousand feet; the highest known peak is about sixteen
thousand.--ED.]

They offer a vast and unexplored field to natural history: no botanist,
no mineralogist, has yet examined them. The first travellers called them
the Glittering mountains, on account of the infinite number of immense
rock crystals, which, they say, cover their surface, and which, when
they are not covered with snow, or in the bare places, reflect to an
immense distance the rays of the sun. The name of Rocky mountains was
given them, probably, by later travellers, in consequence of the
enormous isolated rocks which they offer here and there to the view. In
fact, Millet's rock, and _M'Gillivray's_ above all, appeared to me
wonders of nature. Some think that they contain metals, and precious
stones.

With the exception of the mountain sheep and goat, the animals of the
Rocky mountains, if these rocky passes support any, are not better known
than their vegetable and mineral producti