For this _Encyclopaedia_ (as you may have read in the advertisements) makes a feature of answering all those difficult questions which children ask grown-ups, and which grown-ups really want to ask somebody else. Well, perhaps not all those questions. There are two to which there were no answers in my volume, nor, I suspect, in any of the other volumes, and yet these are the two questions more often asked than any others. "How did God begin?" and "Where do babies come from?" Perhaps they were omitted because the answers to them are so easy. "That, my child, is something which you had better ask your mother," one replies; or if one is the mother, "You must wait till you are grown-up, dear." Nor did I see any mention of the most difficult question of all, the question of the little girl who had just been assured that God could do anything. "Then, if He can do anything, can He make a stone so heavy that He can't lift it?" Perhaps the editor is waiting for his second edition before he answers that one. But upon such matters as "Why does a stone sink?" or "Where does the wind come from?" or "What makes thunder?" he is delightfully informing. But I felt all the time that in this part of his book he really had his eye on me and my generation rather than on the children. No child wants to know why a stone sinks; it knows the answer already--"What else could it do?" Even Sir Isaac Newton was a grown-up before he asked why an apple fell, and there had been men in the world fifty thousand years before that (yes I have been reading _The Outline of History_, too), none of whom bothered his head about gravitation. Yes, the editor was thinking all the time that you and I ought to know more about these things. Of course, we should be too shy to order the book for ourselves, but we could borrow it from our young friends occasionally on the plea of seeing if it was suitable for them, and so pick up a little of that general knowledge which we lack so sadly. Where does the wind come from? Well, really, I don't think I know now. The drawback of all _Guides to Knowledge_ is that one cannot have the editor at hand in order to cross-examine him. This is particularly so in the case of a _Children's Encyclopaedia_, for the child's first question, "Why does this do that?" is meant to have no more finality than tossing-up at cricket or dealing the cards at bridge. The child does not really want to know, but it does want to keep up a friendly conversation, or, if humourously inclined, to see how long you can go on without getting annoyed. Not always, of course; sometimes it really is interested; but in most cases, I suspect, the question, "What makes thunder?" is inspired by politeness or mischief. The grown-up is bursting to explain, and ought to be humoured; or else he obviously doesn't know, and ought to be shown up.