"But," objected Harry, "if we do that, we shall get numbers which have no corresponding letters. I mean that by doing as you suggest we should have 49, 37, 38, and our numbers corresponding to letters only go up as far as 26, which stands for Z, so that method cannot be right. It seems to me that this thing is beyond us, Roger; I do not see what we can make of such an awful jumble of figures." "Gently, my lad, gently," remonstrated Roger, "we will not give it up; we may as well be worrying over this cryptogram as doing nothing, and better, because it helps to pass the time, and keeps our thoughts from-- from--other things," he ended rather lamely. For a few moments they remained silent and cogitating. Do what they would to distract their minds from dwelling upon that ghastly scene in the torture-chamber, the picture was constantly intruding itself upon their imaginations; nor could they forget the ominous words of Alvarez when he instructed the guard to keep them safely, as he would "require them in the future." But, after some little time spent in this dreary form of reverie, Roger started up once more. "Come, Harry," said he, "it is of no use for us to give way to these miserable forebodings; let us get back to the cipher again. It will keep us from thinking; and, besides, we may not have another such favourable opportunity in the future." Harry did not reply, but dismissed his gloomy thoughts, though evidently with an effort, and once again the two leant over their precious paper and cudgelled their brains in the effort to find the proper translation. "Now," resumed Roger, "it seems to me that we may possibly be on the correct track after all with our last grouping of the figures; that is to say, adding the first two and last two figures in each group to one another, and getting a certain number. It looks to me more likely than any of the other methods we tried." "I confess that I am unable to see it," answered Harry. "We have already ascertained that by that method we get, first of all, the numbers 49, 37, and 38, and, as I remarked, we have no letters corresponding to those numbers." "No, I agree with you there," replied Roger. "But how are we to know that Jose selected the number 1 for his letter A, 2 for the letter B, and so on? It is not very likely that he would, as that method of procedure would make the solving of the cipher a fairly easy matter, and we should have translated it by now. It is much more likely that he took some other number for his letter A, say 15, or 40, or any number rather than 1." Harry retorted: "Well, in that case we are just as far off the solution as at first, for how can we possibly tell, except by experiment, what numbers correspond to the right letters? And it would take us weeks to discover it by that method."