CULLUM, Col. GEORGE W.—Military Bridges.

Systems of Military Bridges in use by the U. S. Army; those adopted by the Great European Powers; and such as are employed in British India. With Directions for the Preservation, Destruction, and Re-establishment of Bridges. With 7 folding plates. 8vo, cloth 3 50

DAVIS, C. B., and RAE, F. B.—Hand-Book of Electrical Diagrams and Connections.

Illustrated with 32 full-page illustrations. Second edition. Oblong 8vo, cloth extra 2 00

DIEDRICH, JOHN.—The Theory of Strains.

A Compendium for the Calculation and Construction of Bridges, Roofs, and Cranes. Illustrated by numerous plates and diagrams. 8vo, cloth 5 00

DIXON, D. B.—The Machinist's and Steam-Engineer's Practical Calculator.

A Compilation of Useful Rules, and Problems Arithmetically Solved, together with General Information applicable to Shop-Tools, Mill-Gearing, Pulleys and Shafts, Steam-Boilers and Engines. Embracing Valuable Tables, and Instruction in Screw-cutting, Valve and Link Motion, etc. 16mo, full morocco, pocket form 2 00

DODD, GEO.—Dictionary of Manufactures, Mining, Machinery, and the Industrial Arts.

12mo, cloth 1 50