 Complete the following phrase:  The gas vacuum engine was eventually to become a commercial success. In 1853-1854 Eugenio Barsanti and Felice Matteucci invented and patented the Barsanti-Matteucci engine which was a different form of gas vacuum engine. Developed further by Otto  Langen in Germany, it was put into worldwide production outside Germany by Crossley of Manchester between 1867 and 1877. Examples of this form of engine can be seen working at the Anson Engine Museum. This success arose from a demonstration of the engine at the 