Tom, your knowledge of steam power is unsurpassed; thank you. You mention low gearing on the Shay; was this done strictly through the "ring & pinion " gears on the wheels & side shafts ??? Did the crankshaft offsets at the connecting rods also play into the different gearing ??? Sorry for the automotive terms; I don't know what else to call them. Also, on a rod engine, did a smaller driver diameter equate into a shorter piston stroke ???