We are probably nearing the limit of all we can know about astronomy.

The result was that, if it happened to clear off after a cloudy evening, I frequently arose from my bed at any hour of the night or morning and walked two miles to the observatory to make some observation included in the programme.

As years passed away I have formed the habit of looking back upon that former self as upon another person, the remembrance of whose emotions has been a solace in adversity and added zest to the enjoyment of prosperity.

One of the most beautiful hypotheses ever propounded in physics is ... the Dynamical Theory of Gases

My father was the most rational and the most dispassionate of men.

The mathematician of to-day admits that he can neither square the circle, duplicate the cube or trisect the angle. May not our mechanicians, in like manner, be ultimately forced to admit that aerial flight is one of that great class of problems with which men can never cope... I do not claim that this is a necessary conclusion from any past experience. But I do think that success must await progress of a different kind from that of invention.

A few years later the Naval Academy was founded at Annapolis, and a similar course was pursued to provide it with a corps of instructors.