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way about the sun. The year 1868 at length arrived. On August eighteenth there was to be a remarkable total eclipse of the sun, visible in India. The shadow was one hundred and forty miles broad; the duration of the total phase was more than six minutes. The French sent Mr. Janssen, one of their leading spectroscopists, to observe the eclipse in India and see what he could find out. Wonderful was his report. The red prominences which had perplexed scientists for two centuries were found to be immense masses of glowing hydrogen, rising here and there from various parts of the sun, of a size compared with which our earth was a mere speck. This was not all. After the sunlight reappeared, Janssen began to watch these objects in his spectroscope. He followed them as more and more of the sun came out, and continued to see them until after the eclipse was over. They could be observed at any time when the air was sufficiently clear and the sun high in the sky.

By a singular coincidence this same discovery was made independently in London without any eclipse. Mr. J. Norman Lockyer was then rising into prominence as an enthusiastic worker with the spectroscope. It occurred independently to him and to Mr. Huggins that the heat in the neighbourhood of the sun was so intense that any matter that existed there would probably take the form of a gas shining by its own light. Both of these investigators endeavoured to get a sight of the prominences in this way; but it was not until October twentieth, two months after the Indian eclipse, that Mr. Lockyer succeeded in having an instrument of sufficient