We finally received an answer to the 'mystery' engine featured in the May/June issue of Steam Traction. Paul Ward, 592 Fox Road, Lexington, OH 44904 (firstname.lastname@example.org), believes the engine is an early offering from Canadian manufacturer George White & Son's Co.
Paul notes several items in common with other George White & Son's engines, including: Whistle not fed by steam dome, governor belt with twist, front wheel hub with swooping motion between spokes, quadrant mounted to the back of the boiler/firebox, cylinder mounted just back of the smokestack, low bunkers and a short steam dome. The stack and the the dog-leg flywheel looked unfamiliar to Paul, but a copy of an old catalog image shows this exact same arrangement. Note, too, the stack on the White engine featured on this issue's cover.
Noah Brubaker, 1577 Johnson Mill Road, Lewisburg, PA 17837, was the first person to identify the 'mystery' engine featured in the July/August issue of Steam Traction. Noah correctly identified it as a Leader, manufactured by Marion Manufacturing Co., Marion, Ohio. Noah thinks it's a 12 HP unit, built in 1895 or earlier.
This month's mystery engine comes, as usual, courtesy of John Spalding, 112 Carriage Place, Hendersonville, TN 37035 (email@example.com). There's no information on the photograph, but we can tell you this engine was produced by a company not particularly associated with threshing duties, even though the pictured engine is pulling a thresher.
As ever, the first person to correctly identify the picture, by mail, gets a free copy of Prof. P.F. Rose's Steam Engine Guide. Good hunting, and get those answers in quick.