This was called a gas engine by Old's and sons because the water tubes where heated using gas. I recently purchased this engine and discovered only four existed, with the find of this old engine there are now five known to exisit today. http://aboutsteam.com/index.php/old-engine/
More info comming soon, so please check back. Also please help me fund the project by clicking on the ads found on the same website as the engine, http://aboutsteam.com/index.php/old-engine/