Buffon, the director of the Jardin du Roi... watched... the sun... Besides him.. stood... his latest experiment: four large wooden frames holding between them an array of over 150 mirrors. Screw threads ensured that each mirror was precisely aligned... Buffon had been inspired to conduct the experiment by the famous story of how... Archimedes defended his hometown from an attack by the Roman fleet... [by] focus[ing] the sun's rays onto the ships' wooden hulls. ...In 1747, at the age of thirty-nine, [Buffon] felt it was time to make his mark... Within two minutes the deal plank began to char, then to smoke. Just as it looked as if it would burst into flames, however, the sun disappeared behind a cloud. ...That summer, crowds flocked... to see the now celebrated scientist set fire to buildings over two hundred feet away.
Georges-Louis Leclerc