Chap. 1. How Work is Measured by a Unit, both with and without reference to a Unit of Time--Chap. 2. The Work of Living Agents, the Influence of Friction, and introduces one of the most beautiful Laws of Motion--Chap. 3. The principles expounded in the first and second chapters are applied to the Motion of Bodies--Chap. 4. The Transmission of Work by simple Machines--Chap. 5. Useful Propositions and Rules. * * * * * _The Practical Millwright’s and Engineer’s Ready Reckoner_; or Tables for finding the diameter and power of cog-wheels, diameter, weight, and power of shafts, diameter and strength of bolts, etc. By THOMAS DIXON. Fourth edition, 12mo, cloth, 3_s._ CONTENTS: Diameter and Power of Wheels--Diameter, Weight, and Power of Shafts--Multipliers for Steam used Expansively--Diameters and Strength of Bolts--Size and Weight of Hexagonal Nuts--Speed of Governors for Steam Engines--Contents of Pumps--Working Barrels--Circumferences and Areas of Circles--Weight of Boiler Plates--French and English Weights and Measures, etc. * * * * * _The Principles of Mechanics and their Application to Prime Movers, Naval Architecture, Iron Bridges, Water Supply, etc._ By W. J. MILLAR, C.E., Secretary to the Institution of Engineers and Shipbuilders, Scotland. Crown 8vo, cloth, 4_s._ 6_d._ * * * * * _A Practical Treatise on Mill-gearing, Wheels, Shafts, Riggers, etc._; for the use of Engineers. By THOMAS BOX. Crown 8vo, cloth, _with 11 plates_, second edition, 7_s._ 6_d._ * * * * * _Mining Machinery_: a Descriptive Treatise on the Machinery, Tools, and other Appliances used in Mining. By G. G. ANDRÉ, F.G.S., Assoc. Inst. C.E., Mem. of the Society of Engineers. Royal 4to, uniform with the Author’s Treatise on Coal Mining, containing 182 _plates_, accurately drawn to scale, with descriptive text, in 2 vols., cloth, 3_l._ 12_s._ CONTENTS: Machinery for Prospecting, Excavating, Hauling, and Hoisting--Ventilation--Pumping--Treatment of Mineral Products, including Gold and Silver, Copper, Tin, and Lead, Iron, Coal, Sulphur, China Clay, Brick Earth, etc. * * * * * _The Pattern Makers Assistant_; embracing Lathe Work, Branch Work, Core Work, Sweep Work, and Practical Gear Construction, the Preparation and Use of Tools, together with a large collection of Useful and Valuable Tables. By JOSHUA ROSE, M.E. With 250 _illustrations_. Crown 8vo, cloth, 10_s._ 6_d._ * * * * * _The Science and Art of the Manufacture of Portland Cement_, with observations on some of its constructive applications, _with numerous illustrations_. By HENRY REID, C.E., Author of ‘A Practical Treatise on Concrete,’ etc., etc. 8vo, cloth, 18_s._ * * * * *