to an intolerable excess, who
would not look at these last boundaries to man's knowledge with deep but
ill-defined sensations?"

Hamerton, whose wide experience and artistic power make his opinion
especially important, says:--

"I know nothing in the visible world that combines splendour and purity
so perfectly as a great mountain entirely covered with frozen snow and
reflected in the vast mirror of a lake. As the sun declines, its
thousand shadows lengthen, pure as the cold green azure in the depth of
a glacier's crevasse, and the illuminated snow takes first the tender
colour of a white rose, and then the flush of a red one, and the sky
turns to a pale malachite green, till the rare strange vision fades into
ghastly gray, but leaves with you a permanent recollection of its too
transient beauty."[7]

Wallace especially, and very justly, praises the description of tropical
forest scenery given by Belt in his charming _Naturalist in
Nicaragua_:--

"On each side of the road great trees towered up, carrying their crowns
out of sight amongst a canopy of foliage, and with lianas hanging from
nearly every bough, and passing from tree to tree, entangling the giants
in a great network of coiling cables. Sometimes a tree appears covered
with beautiful flowers which do not belong to it, but to one of the
lianas that twines through its branches and sends down great rope-like
stems to the ground. Climbing ferns and vanilla cling to the trunks, and
a thousand epiphytes perch themselves on the branches. Amongst these are
large arums that send down long aerial roots, tough and strong, and
universally used instead of cordage by the natives. Amongst the
undergrowth several small species of palms, varying in height from two
to fifteen feet, are common; and now and then magnificent tree ferns
send off their feathery crowns twenty feet from the ground to delight
the sight by their graceful elegance. Great broad-leaved heliconias,
leathery melastomae, and succulent-stemmed, lop-sided leaved and
flesh-coloured begonias are abundant, and typical of tropical American
forests; but not less so are the cecropia trees, with their white stems
and large palmated leaves standing up like great candelabra. Sometimes
the ground is carpeted with large flowers, yellow, pink, or white, that
have fallen from some invisible tree-top above; or the air is filled
with a delicious perfume, the source of which one seeks around in vain,
for the flowers that c