Page:A Voyage in Space (1913).djvu/167

Rh coastline has been made straight, various islands, such as Anglesea and the Hebrides have been swept away, the Thames and Severn have given place to two straight canals, and there is Home Rule in Ireland! Of all this you as Martians could detect nothing, even through the best telescope. How, then, are we to find signs of life in Mars? You will perhaps agree with me that it is a very difficult quest.

With other planets we can see less still, either because they are too near the Sun, like Mercury and Venus, or because they are even further away than Mars, like Jupiter and others. Here are two pictures of Jupiter showing the "red spot" (see Fig. 41). We learn from it that Jupiter rotates on its axis as the Earth does, because the red spot goes round: it crosses the disc, disappears on the other side, and then reappears again. It comes back to the same place pretty regularly after about 10 hours, and other spots on Jupiter, not so large as the red spot but quite noticeable, also return to their places in