Hadamard on Picard
In 1936 French scientists gathered to celebrate the 70th birthday of Jacques Hadamard. At his jubilee meeting Hadamard spoke about those who had influenced him in his career. Congratulating Hadamard at his jubilee, Emile Picard remarked that Hadamard probably did not remember his lessons "on modest problems in rational mechanics." Hadamard replied:-
In addressing myself to Monsieur Picard, I must first of all protest. No, I have never forgotten the lessons you gave during the second year of the École, and I am even able to add to your recollections. It is perfectly true that you had assumed the task (should I say burden?) of training us in this artificial and lamentably monotonous exercise, which Mechanics is in the degree programme. You were able to make it almost interesting; I have always wondered how you went about this, because I was never able to do it when it was my turn. But you also escaped, you introduced us not only to hydrodynamics and turbulence, but to many other theories of mathematical physics and even of infinitesimal geometry: all this in lectures, the most masterly I heard, in my opinion, where there was not one word too many nor one word too little, and where the essence of the problem and the means used to overcome it appeared crystal clear, with all secondary details being treated thoroughly and at the same time consigned to their proper place.
All mathematicians know, on the other hand, what a marvellous stimulus for research your mysterious and disconcerting theorem on entire functions was, and still is, because the subject has lost nothing of its topicality. I can say that I owe to it a great part of the inspiration of my first years of work.
Much later Hadamard wrote in Picard's obituary:-
A striking feature of Picard's scientific personality was the perfection of his teaching, one of the most marvellous, if not the most marvellous that I have known.