our knowledge of Nature, especially when on foreign stations. So
far from it, drawings ought always to be valuable, whether of
plants, animals, or scenery, provided only they are accurate; and
the more spirited and full of genius they are, the more accurate
they are certain to be; for Nature being alive, a lifeless copy of
her is necessarily an untrue copy. Most thankful to any officer for
a mere sight of sketches will be the closest botanist, who, to his
own sorrow, knows three-fourths of his plants only from dried
specimens; or the closest zoologist, who knows his animals from
skins and bones. And if any one answers--But I cannot draw. I
rejoin. You can at least photograph. If a young officer, going out
to foreign parts, and knowing nothing at all about physical science,
did me the honour to ask me what he could do for science, I should
tell him--Learn to photograph; take photographs of every strange bit
of rock-formation which strikes your fancy, and of every widely-
extended view which may give a notion of the general lie of the
country. Append, if you can, a note or two, saying whether a plain
is rich or barren; whether the rock is sandstone, limestone,
granitic, metamorphic, or volcanic lava; and if there be more rocks
than one, which of them lies on the other; and send them to be
exhibited at a meeting of the Geological Society. I doubt not that
the learned gentlemen there will find in your photographs a valuable
hint or two, for which they will be much obliged. I learnt, for
instance, what seemed to me most valuable geological lessons from
mere glances at drawings--I believe from photographs--of the
Abyssinian ranges about Magdala.

Or again, let a man, if he knows nothing of botany, not trouble
himself with collecting and drying specimens; let him simply
photograph every strange and new tree or plant he sees, to give a