The Probert Encyclopaedia of Science & Technology

LEWIS

The lewis was a contrivance for lifting stones which was used by the ancient Romans. It received its name from a French architect who revived the instrument and named it after his master Louis XIV. The lewis consists of two dovetail tenons, which are expanded by a key in a dovetail mortise in the stone, and shackled to a hoisting-chain. The dovetail pieces are first inserted, and then forced apart by the middle key, so as to occupy the undercut portion of the mortise. All three are then shackled to the lifting-chain.
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