Jan Felkl (1817-1887) was perhaps the most successful nineteenth century globe manufacturer: he started his professional life as a postman in Prague before moving into globe manufacture in around 1850, in co-operation with photographer and engraver Vaclav Merklas. In 1855 he produced 800 globes; by 1873 he was producing 15,000, and employing up to 40 people. His terrestrial and celestial globes, as well as lunar globes, planetaria, telluria, lunaria and induction globes, were produced in seventeen different languages. It was one of Felk's best known authors, Otto Delitsch (1821-1882), a geography teacher at the University of Leipzig, who developed the notion of tonal graduation of height for maps and globes. Part of the reason for Felkl's success was undoubtably due to the Austrian Schools Law of 1870 which stipulated that every school should have a globe. However Felk's products, as well as those of other successful manufacturers of school globes and planetaria Schotte and Schönninger, are nowadays reasonably scarce as they were not considered worth conserving.