Heavier-than-air flying machines are impossible.

Mathematics is the only good metaphysics.

[Referring to Fourier's mathematical theory of the conduction of heat] ... Fourier's great mathematical poem.

Fourier's theorem is not only one of the most beautiful results of modern analysis, but it may be said to furnish an indispensable instrument in the treatment of nearly every recondite question in modern physics.

Mathematics is the only true metaphysics.

Science is bound, by the everlasting vow of honour, to face fearlessly every problem which can be fairly presented to it.

Symmetrical equations are good in their place, but ' vector ' is a useless survival, or offshoot from quaternions, and has never been of the slightest use to any creature.