Model of cylinder with separate condenser, formerly described as the "original" model.
Second model separate condenser, formerly described as the "original" model. Made by James Watt (1736-1819), 1765. Early Newcomen engines were inefficient as their working cycle entailed continual heating and cooling of the cylinder, which wasted fuel. The separate condenser meant the steam was condensed in a separate chamber, allowing the cylinder to be kept hot and greatly increasing fuel efficiency. This model was probably made immediately after the first although Watt seems to have quickly forgotten about it. It was preserved not in Watt's garret workshop but, it appears, on the premises of James Watt & Co. The model is more elaborate than the first (preserved under Inventory number 1924-792) but was probably less successful - the pasteboard seal for the cylinder would have caused problems during operation, and the model bears evidence of substantial alterations.