“Rather a profound question for a lady!” I said to myself, holding, with the conceit so natural to Man, that Woman's intellect is essentially shallow. And I considered a minute before replying. “If you mean living minds, I don't think it's possible to decide. There is so much written Science that no living person has ever read: and there is so much thought-out Science that hasn't yet been written. But, if you mean the whole human race, then I think the minds have it: everything, recorded in books, must have once been in some mind, you know.” “Isn't that rather like one of the Rules in Algebra?” my Lady enquired. (“Algebra too!” I thought with increasing wonder.) “I mean, if we consider thoughts as factors, may we not say that the Least Common Multiple of all the minds contains that of all the books; but not the other way?” “Certainly we may!” I replied, delighted with the illustration. “And what a grand thing it would be,” I went on dreamily, thinking aloud rather than talking, “if we could only apply that Rule to books! You know, in finding the Least Common Multiple, we strike out a quantity wherever it occurs, except in the term where it is raised to its highest power. So we should have to erase every recorded thought, except in the sentence where it is expressed with the greatest intensity.” My Lady laughed merrily. “Some books would be reduced to blank paper, I'm afraid!” she said. “They would. Most libraries would be terribly diminished in bulk. But just think what they would gain in quality!” “When will it be done?” she eagerly asked. “If there's any chance of it in my time, I think I'll leave off reading, and wait for it!” “Well, perhaps in another thousand years or so--” “Then there's no use waiting!”, said my Lady. “Let's sit down. Uggug, my pet, come and sit by me!” “Anywhere but by me!” growled the Sub-warden. “The little wretch always manages to upset his coffee!” I guessed at once (as perhaps the reader will also have guessed, if, like myself, he is very clever at drawing conclusions) that my Lady was the Sub-Warden's wife, and that Uggug (a hideous fat boy, about the same age as Sylvie, with the expression of a prize-pig) was their son. Sylvie and Bruno, with the Lord Chancellor, made up a party of seven. {Image...A portable plunge-bath} “And you actually got a plunge-bath every morning?” said the Sub-Warden, seemingly in continuation of a conversation with the Professor. “Even at the little roadside-inns?”