t looked a fairly easy cypher; but as a
matter of fact, I don't think it's easy at all. One assumes, of course,
that the figures stand for letters, and on that assumption two or three
peculiarities are noticeable. First, the highest number written here is
23, so that all the letters indicated, in whatever order they may come,
are within the compass of the twenty-six letters of the alphabet. Next,
the numbers most frequently repeated, if we except the noughts, are 5
and 20, which occur seven times each. Now, the vowel most frequently
occurring in average English writing is e, and you will at once perceive
that e is number five in the alphabet, counting from the beginning.
More, if we go on counting so, we shall find that 20 is _t_, which is
one of the most frequently occurring consonants. This would seem to hint
that the cypher is of the very simplest description, consisting of the
mere substitution of figures for letters in the exact order of the
alphabet. But what, then, of the noughts? What can they mean? More
especially when we consider that in three places there are actually four
noughts in succession; for, of course, no letter is repeated four times
successively in any English word, nor in any foreign word that I can
imagine. But let us put down the letters in substitution for the
figures, on the supposition that the figures stand for letters in their
alphabetical order, leaving the noughts as they are. Then we get this."

I rapidly pencilled the letters on the spare paper, thus:--_i, h, n, d,
t, r, e, i; 0, s, t, 0, c, i, h, e; c, w, 0, 0, e, m, n, s; s, t, 0, 0,
0, 0, f, a; e, t, 0, 0, 0, 0, c, v; a, 0, 0, 0, 0, 0, r, e; a, h, t, k,
r, i, e, t; l, e, w, n, n, a, a, t_.

"See there," I said. "Now, I can make nothing of that. When I come to
examine the comparative frequency of the different letters, I find them
much as they might be expected to be in a sentence of normal English,
and any change would destroy the proportion. _E_ and _t_ are the most
frequent, and then come _a, n, i, r, s,_ and _c_. But as they stand
they all mean nothing. It is possible that this may be one of the
difficult variable letter cyphers, which Hewitt might read, but I can't.
But even then, if the values of the letters change as they would do,
they would get out of their normal proportions of frequency; so that a
variable letter cypher seems unlikely. And there is another oddity.
Look, and you will see that, counting the noughts in, the le