LETTERS ON INTERNATIONAL COPYRIGHT (1867) 50

THE UNITY OF LAW: As Exhibited in the Relations of Physical, Social, Mental, and Moral Science (1872). In one volume, 8vo., pp. xxiii., 433. Cloth. $3.50

CHAPMAN.—A Treatise on Ropemaking:

As Practised in private and public Rope yards, with a Description of the Manufacture, Rules, Tables of Weights, etc., adapted to the Trades, Shipping, Mining, Railways, Builders, etc. By Robert Chapman, 24mo. $1.50

COLBURN.—The Locomotive Engine:

Including a Description of its Structure, Rules for Estimating its Capabilities, and Practical Observations on its Construction and Management. By Zerah Colburn. Illustrated.
A new edition. 12mo. $1.25

CRAIK.—The Practical American Millwright and Miller.

By David Craik, Millwright. Illustrated by numerous wood engravings, and two folding plates. 8vo. $5.00

DE GRAFF.—The Geometrical Stair Builders' Guide: