Jacob Metzu, scientifically Metius, discovers the telescope by chance, as Newton did gravitation and Christopher Columbus, America. Let us open a parenthesis: there is no chance in the creation of "Orestes" or of "Paradise Lost." A _chef-d'œuvre_ is the offspring of will. After Metzu comes Galileo, who improves the discovery of Metzu; then Kepler, who improves on the improvement of Galileo; then Descartes, who, although going somewhat astray in taking a concave glass for eyepiece instead of a convex one, fructifies the improvement of Kepler; then the Capuchin Reita, who rectifies the reversing of objects; then Huyghens, who makes a great step by placing the two convex glasses on the focus of the objective; and in less than fifty years, from 1610 to 1659, during the short interval which separates the "Nuncius Sidereus" of Galileo from the "Oculus Eliæ et Enoch" of Father Reita, behold the original inventor, Metzu, obliterated. And it is constantly the same in science. Vegetius was Count of Constantinople; but that is no obstacle to his tactics being forgotten,--forgotten like the strategy of Polybius, forgotten like the strategy of Folard. The pig's-head of the phalanx and the pointed order of the legion have for a moment re-appeared, two hundred years ago, in the wedge of Gustavus Adolphus; but in our days, when there are no more pikemen as in the fourteenth century, nor lansquenets as in the seventeenth, the ponderous triangular attack, which was in other times the base of all tactics, is replaced by a crowd of Zouaves charging with the bayonet. Some day, sooner perhaps than people think, the charge with the bayonet will be itself superseded by peace, at first European, by-and-by universal, and then a whole science--the military science--will vanish away. For that science, its improvement lies in its disappearance.