Page:Popular Science Monthly Volume 82.djvu/214

210 windings and caprices of the continuous laws that join quantities together, there is not one of his works which has not the masterly touch, not one of his fifteen hundred publications which does not show the lion's claw.

At the age of twenty-seven, the Faculty of Sciences offered this young conqueror its chair of physical mechanics. At thirty-three the Academy of Sciences opened its door, an example soon followed by the learned academies of the entire world; for there was no body of scientists in Europe or America which did not feel that it honored itself in adjoining the cooperation of Henri Poincaré.

But the mathematical sciences were for this illustrious analyst only a manifold and prodigious measuring instrument admirably adapted to the comparative study of the phenomena of the universe. This instrument he set himself to use, and what skill he displayed! At the age of thirty, he astonished the physicists by his critique of the general principles of their science; that was but the beginning of bold speculations which led him year by year up to the very edge of the unknown, to the constitution of matter, to the paradoxical mechanics that sprung up after the unexpected discovery of the mysterious radioactivity.

Yet this was only part of his activity: geodesy, cosmogony, astronomy, philosophy of science, he included them all, penetrated all, explored all. His celestial mechanics would be glory enough. It was this that revealed him first to a wide public. King Oscar II. of Sweden, Mæcenus of science, enlightened and generous, in 1887 opened an international competition in mathematics. In 1889, at the end of the contest, France learned with joy that the great gold medal, supreme prize of this new tournament, had been awarded to one of her children, a young scientist thirty-five years of age, for a marvelous study of the mechanical stability of our universe; and the name of Henri Poincaré was famous.

Gentlemen, the Theban hero dying after two victories said: "I leave two immortal daughters." This hero of the world of thought who has just succumbed, leaves in the ideal world, as real as the other world, an immortal posterity which will guide the future researches of men. Indeed his life will remain an example as harmonious in its faultless lines as the orbits of those stars whose eternal past and eternal future he desired to know.

To this eulogy of Professor Painlevé certainly I could add nothing, and it does not seem necessary to enumerate the many other honors of Poincaré's. I shall undertake only to consider briefly his conception of science in its chief phases, and in the light of this conception to consider at more length in particular his ideas of research. As an investigator his opinions carry extraordinary weight, as he was a subtle philosopher and a skilled psychologist. We may treat three phases of scientific activity as distinct, pure science, industrial science and what we may call euthenic science.

In speaking of the death of Brouardel, who did much for the study of hygiene, and had helped in preventing three invasions of cholera, without disturbing commerce, Poincare said before the Académie des Sciences:

In this direction scientists can scarcely count on the satisfaction of discovering general laws, exterior as it were to space and time, but there are other