Ten decimal places of π are sufficient to give the circumference of the earth to a fraction of an inch, and thirty decimal places would give the circumference of the visible universe to a quantity imperceptible to the most powerful microscope.

One hardly knows where, in the history of science, to look for an important movement that had its effective start in so pure and simple an accident as that which led to the building of the great Washington telescope, and went on to the discovery of the satellites of Mars.

All attempts at artificial aviation are not only dangerous to human life, but foredoomed to failure from the engineering standpoint.

Construction of an aerial vehicle which can carry even a single man . . . requires the discovery of some new metal or force. Even with such a discovery, we could not expect one to do more than carry its owner.

Flight by machines heavier than air is unpractical and insignificant, if not utterly impossible.

James Edward Oliver might have been one of the great mathematicians of his time had he not been absolutely wanting in the power of continuous work.

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