"The opinion seems to have got abroad, that in a few years all the great physical constants will have been approximately estimated, and that the only occupation which will then be left to men of scienc…"

"The mind can only attend to one thing at a time."

"The velocity of light is a quantity of which we have now a more accurate knowledge than of any other physical constant."

"It is a good thing to have a great many ideas, and a great many of them bad."

"The first thing that I always do is to try to understand the problem."