I cannot doubt, from what I
have seen in the parts I traversed, that there is, but the above is
enough to justify my assertion that "a very considerable part of the
States is desert."

I would I could give a map here of the States with all the deserts
painted yellow. No map extant delineates these vast wastes. I am
afraid to hazard a guess what proportion the said painted parts would
bear to the whole, but enough, I am sure, to make the reader wonder
as I did.

How enormous these deserts are may be judged of by the fact that the
four first states in the list above are together roughly about one
third larger than France ... and that the far greater part of them,
to say the least, are howling wastes!

A great part of these vast tracts are as truly desert as those in
Africa. Sand and nothing but sand; water would have no effect as
regards fertilization, and, besides, there _is_ no water. But other
parts are different. Not more tempting to the eye, what looks like
sand has vitality in it. Water produces a wonderful transformation,
and crops, trees--everything will grow with its aid. Thus, in this
better class of desert and in the favoured spots where water is
procurable, the said blank waste becomes a smiling spot. Such is the
desert the Mormons have fertilized, such, as a rule, the deserts in
California. Much of the splendid fruit that state produces has its
birthplace in such localities.

Where the deserts of the last-mentioned kind are found, did anything
like a moderate rainfall happen yearly, they, of course, would not
exist. But rain in these localities is very rare, as indeed it is all
over the world in such spots. The want of rain, I conceive, _makes_
the desert, and the arid waste responds by keeping off the rain. It
is well known vegetation conduces to rainfall, and that a country
thickly wooded, when cleared, has less rain after. I have myself seen
striking instances of this. On the other hand, vegetation and rain
increase simultaneously. It _may_ be, therefore, that, in the course
of very many years, a portion of the American deserts will disappear,
for where the soil has any vitality in it, and water is procurable,
artificial means will bring vegetation, which again, little by
little, will increase the rainfall; until at last (it may take
centuries) the now said desert tracts will thrive with the rain from
heaven alone.

While on the subject of rain, I would mention some curious facts.
From what we kno