Сегодня родился Егоров Николай Григорьевич
On September 19, 1849 in St. Petersburg Egorov Nikolay Grigoryevich was born. This is a Russian physicist, professor of physics in army medical college, an assistant to the managing director of the main Board of Weights and Measures, and its managing director since 1907. Egorov was the author of researches on optics. His known scientific works on this subject are "An electric photometer" and "Atmospheric lines of a solar range".