though they have discovered only four of those parts, there will be thousands—perhaps thirty thousand more—yet discovered.' This planet he believed to have been lost by explosion.
"With great kindness and patience he referred me, in the course of my attempts to talk with him, to a theorem in Newton's 'Principles of Natural Philosophy' in which the time that the light takes to travel from the sun is proved with a simplicity which requires but a few steps in reasoning. In talking of some inconceivably distant bodies, he introduced the mention of this plain theorem, to remind me that the progress of light could be measured in the one case as well as the other. Then, speaking of himself, he said, with a modesty of manner which quite overcame me, when taken together with the greatness of the assertion: 'I have looked further into space than ever human being did before me. I have observed stars, of which the light, it can be proved, must take two millions of years to reach this earth.'
"I really and unfeignedly felt at this moment as if I had been conversing with a supernatural intelligence. 'Nay, more,' said he, 'if those distant bodies had ceased to exist two millions of years ago, we should still see them, as the light would travel after the body was gone...' These were Herschel's words; and if you had heard him speak them, you would not think he was apt to tell more than the truth.
"After leaving Herschel I felt elevated and overcome; and have in writing to you made only this memo-
