"What? what? oh, quick!" they begged.
"I think some one has written all this in what they call a—a 'cipher.' I've heard of such things. Father told me people often send messages over the telegraph or cable in cipher—"
"But what is that? How?" demanded Margaret.
"Why, they have certain words or expressions which stand for other words or even whole sentences. And you can't understand the message unless you have the 'code' or explanation. For instance, a man may cable just the words 'Pay Smith' to his broker, and that may mean 'Buy me five thousand bushels of wheat to-day.'"
"Yes, but that isn't a bit like what's here," argued Margaret.
"No, but it's the same idea," Corinne declared. "I think in this case some one has taken certain signs to represent the different letters of the alphabet. First I thought that perhaps each sign might stand for a different word. But that could hardly be, because there are so many words, one could hardly find signs enough to go round. And besides, I notice in looking through the book that there are comparatively few signs, and they are constantly repeated." She fell to gazing silently at the book again, while the others watched, still more fascinated by the discoveries she was making. Presently she looked up again.
"I've found out something else, I think. Do you see that sign of the triangle? Well, if you notice, that occurs more frequently than any of the others. In the first five lines there are more than fourteen of them, and no other sign happens as frequently as that. Now, if these signs stand for letters, that couldn't be a letter, even if it were one of the commonest, like 'a' or 'i' or 'e'—"
"What can it be then?" whispered Margaret, in a voice so tense that they all laughed.
"I think it means the space between the words!" vouchsafed Corinne. "You see, there'd have to be something to indicate spaces. You couldn't have the words all jumbled up together. It wouldn't make sense!"