books.google.fr - A physicist and an inventor, Jules Janssen (1824-1907) devoted his life to astronomical research. He spent many years traveling around the world to observe total Solar eclipses, demonstrating that a new era of science had just come thanks to the use of both spectroscopy and photography, and persuading...https://books.google.fr/books/about/The_Astronomer_Jules_Janssen.html?hl=fr&id=3YaAup49nqoC&utm_source=gb-gplus-shareThe Astronomer Jules Janssen
