A Dovetail Joint
Shape of Tenon and Mortise
The illustration shows an unusual dovetail joint, which, when put together properly is a puzzle. The tenon or tongue of the joint is sloping on three surfaces and the mortise is cut sloping to match. The bottom surface of the mortise is the same width at both ends, the top being tapering toward the base of the tongue.
Contributed by Wm. D. Mitchell, Yonkers, New York.