Fluorescent lamp began with the Geissler tube continued as even better vacuums were produced. The most famous was the evacuated tube used for scientific research by William Crookes. That tube was evacuated by the highly effective mercury vacuum pump created by Hermann Sprengel. Research conducted by Crookes and others ultimately led to the discovery of the electron in 1897 by J. J. Thomson and X-rays in 1895 by Wilhelm Roentgen. But the Crookes tube, as it came to be known, produced little light because the vacuum in it was too good and thus lacked the trace amounts of gas that are needed
Wilhelm Dürr the Younger assistant professor at the Munich Academy of Fine Arts and, in 1892, professor. There he taught mainly life classes. At the end of his life, he was seriously ill and only painted a few pictures. In Dachau, Wilhelm-Dürr-Straße is named in honour of the painter. Wilhelm Dürr the Younger Wilhelm Dürr the Younger (24 August 1857, Freiburg im Breisgau, Baden – 23 February 1900, Munich) was a German painter and draughtsman, as well as a professor at the Academy of Fine Arts in Munich. Dürr was the son of the painter Wilhelm Dürr the Elder (1815–1890) and his wife Berta