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You see the outline of Africa and other well-known outlines; these need not be regarded very closely; they are the same in both pictures. The only difference is in the British Isles. To make these two pictures, a globe was photographed twice, in as nearly the same conditions as possible, with one exception: the British Isles were cut out in paper, in the first case in their usual shape, in the second case in very much altered shape. Fig. 40. You will see the alterations in a moment when I put both pictures on the screen; but first I want you to try whether you can see them from Mars. If such alterations were made in England, could the Martians armed with our best telescope detect them at all? Well, you are practically in that position; what do you say? I fancy you cannot detect much difference. Now let us look at Fig. 40 on a scale which will show us their real differences; you see that our well-known wavy