Quaternions came from Hamilton after his really good work had been done, and though beautifully ingenious, have been an unmixed evil to those who hav… - William Thomson, 1st Baron Kelvin

There cannot be a greater mistake than that of looking superciliously upon the practical applications of science. The life and soul of science is its practical application; and just as the great advances in mathematics have been made through the desire of discovering the solution of problems which were of a highly practical kind in mathematical science, so in physical science many of the greatest advances that have been made from the beginning of the world to the present time have been made in earnest desire to turn the knowledge of the properties of matter to some purpose useful to mankind.

Every boy... should be able by the age of 12 to write his own language with accuracy and some elegance; he should have a reading knowledge of French, and be able to translate Latin and easy Greek authors, and have some acquaintance with German. Having learned thus the meaning of words... a boy should study Logic, so as to be able to apply his words sensibly.

Now I think hydrodynamics is to be the root of all physical science, and is at present second to none in the beauty of its mathematics.