The French "Commission des Phares" (Commission of Lighthouses) was established by Napoleon in 1811, and placed under the authority of Fresnel's employer, the Corps of Bridges and Roads. As the members of the Commission were otherwise occupied, it achieved little in its early years. But on 21 June 1819—three months after winning the physics "Grand Prix" of the Academy of Sciences for his celebrated memoir on diffraction—Fresnel was "temporarily" seconded to the Commission on the recommendation of François Arago (a member since 1813), to review possible improvements in lighthouse illumination.