The indispensibility to each other of pure and applied science

I ACCEPTED, with considerable hesitation, the invitation to address you on the general subject of the relations of pure and applied science; and in particular of physics and engineering. Two yearsago, Colonel Carty in his presidential address to the A. I. E. E. spoke upon this subject in a way which met with the hearty approval of all physicists. He has done more than most to foster cooperation between us and to bring about great practical results by utilizing the method of scientific research. What is there left for me to say? One thing that I want to say is that Colonel Carty in his addresses has very generously acknowledged the debt which applied science owes to what is called pure science, and I wish to emphasize the reciprocal obligation. There is the obvious indebtedness for improved and convenient apparatus, material and machinery. How fast should we get on if we had, like Faraday, to insulate our own wire and make electromagnets out of links of anchor chain? The co-existence in cooperation between the two phases of science, which we call pure and applied, is of the very essence of the spirit and method of modern science, and is necessary to its existence.