Page:In the high heavens.djvu/296

 It cannot be denied that local if not general changes in the sun's temperature must be the accompaniment of the violent disturbances by which our luminary is now and then agitated. It is, indeed, well known that there are occasional outbreaks of solar activity, and that these recur in a periodic manner; it is accordingly not without interest to notice that the present year has been one of these periods of activity. We are certainly not going so far as to say that any connection has been definitely established between a season of exuberant sun-spots and a season remarkable for excessive warmth, but, as we know that there is a connection between the magnetic condition of the earth and the state of solar activity, it is by no means impossible that climate and sun-spots may also stand in some relationship to each other.

As to the activity of the sun during the hot summer, a very striking communication was made at the time by one of the most distinguished American astronomers, Professor George E. Hale. He has invented an ingenious apparatus for photographing on the same plate at one exposure both the bright spots and the protuberances of the sun. Professor Hale delivered an interesting lecture at a meeting of the American Association for the Advancement of Science at Rochester. A report of this lecture appeared in Nature, in which we are told of a remarkable application of Professor Hale's apparatus. On the 15th of July a photograph of the sun showed a large spot. Another photograph taken in a few minutes exhibited a bright band; twenty-seven minutes later a further exposure displayed an outburst of brilliant faculæ all over the spot. At the end of an hour the faculæ had all vanished, and the spot was restored to its original condition. It was not