Photogravure after a painting by Walter Petersen of Eugen Langen (1839-1895), German engineer and businesman who designed the 'Schwebebahn', the monorail for the German city of Wuppertal. Work began in 1893 and Langen obtained a patent for the design in 1899. The 'Schwebebahn' was completed in 1901 and it is one of the oldest types of monorail in existence. Langen also started the world's first engine factory. From a collection of portraits of scientists published by Photographische Gesellschaft, Berlin, 1910.
© Science Museum / Science & Society Picture Library