BENJAMIN BAILLAUD was born in 1848, a year of revolutions, and his peaceful life, which came to an end on July 8 last, was crossed by two wars which shook France to her foundations. Passing through the ficole Normale, he became an assistant to Leverrier at the Observatory of Paris, arid also his substitute at the Sorbonne. After the defeat of France in 1870, Baillaud, then at the meridian of his energy and clearness, shared in the immense revival of France which had its place in the sciences, as well as in other directions. Sent to Toulouse, to reform the Observatory in succession to Tisserand, and afterwards as dean of the Faculty of Sciences, he performed these duties with singular zeal and effectiveness. He modernised the Observatory and brought many men, since famous, to the University; in the former respect we may mention only, as an instance of his foresight, that he developed as a pioneer, celestial photography. He also established at the greatest height then known, more than 9,500 ft., an observatory, chiefly, of course, meteorological, on the Pic du Midi de Bigorre, in the Pyrenees.