Page:A Voyage in Space (1913).djvu/250

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A VOYAGE IN SPACE

moves faster in the middle and slower near the banks, and the Sun is like the stream, rather than the escalator. At any rate the spots move quicker when they are near his equator, and slower near the poles; and the slopes of the groups of marks in Mr. Maunder's diagram correspond to the paces of different spots; there is no difficulty in finding a place on the Sun which would suit any of the slopes in the diagram. Hence he concludes confidently, and we may agree with him, that the magnetic storms on our Earth originate in some way on the Sun; and this alone suggests pretty clearly that the Sun himself must be magnetic, at any rate, in certain parts. Professor Hale has carried the story further and told us where to look for the origins. He has enormously increased our daily work in observing the Sun; for, to take only one instance, he has shown that we must photograph him not once a day only, as is done at Greenwich, but many times and in different colours, since each colour gives us a different picture. But then Professor Hale has also banded astronomers together into a great union for observing the Sun, as Bode banded them a century ago to discover the missing planet. This new company of "astronomical police" is to photograph the Sun in all sorts of ways as often as possible; they are scattered round the world so that when the Sun is hidden at one place it may be shining in another. At present there is a rather wide gap in the ring of observations; but we are hoping that either Japan or Australia or New Zealand, or perhaps all three, will establish solar observatories; indeed, a rich and generous man,