The Shay locomotive was the most widely used geared steam locomotive. It was built to the patents of Ephraim Shay, a school teacher, who has been credited with the popularization of the concept of a geared steam locomotives. Although the design of Ephraim Shay's early locomotive differed from later ones, there is a clear line of development that joins all Shay's steam locomotives; Shay locomotives had regular fire-tube boilers offset to the left to provide space for, and counterbalance the weight of, a two or three cylinder "motor," mounted vertically on the right with longitudinal drive shafts extending fore and aft from the crankshaft at wheel axle height. These shafts had universal joints and square sliding prismatic joints to accommodate the swiveling trucks. Each axle was driven by a separate bevel gear, with no side rods. The strength of these engines is that all wheels, including, in some engines, those under the tender, are driven so that all the weight develops tractive effort. Available in 8 x 11 b & w on Hahnemuhle museum etching fine art inkjet paper, and each photograph is personally approved and hand-signed by me, the artist.