 Complete the following phrase:  He is most known for his inventions; the best known of these is the Scheutzian calculation engine, invented in 1837 and finalized in 1843. This machine, which he constructed with his son Edvard Scheutz, was based on Charles Babbages difference engine. In 1851 they obtained funds from government to build an improved model, which was created in 1853 was roughly the size of a piano, and subsequently demonstrated at the 