chran, J. Concrete and Reinforced Concrete Specifications 8vo, *2 50

---- Inspection of Concrete Construction 8vo, *4 00

---- Treatise on Cement Specifications 8vo, *1 00

Cocking, W. C. Calculations for Steel-Frame Structures 12mo, *2 25

Coffin, J. H. C. Navigation and Nautical Astronomy 12mo, *3 50

Colburn, Z., and Thurston, R. H. Steam Boiler
Explosions. (Science Series No. 2.) 16mo, 0 50

Cole, R. S. Treatise on Photographic Optics 12mo, 1 50

Coles-Finch, W. Water, Its Origin and Use 8vo, *5 00

Collins, J. E. Useful Alloys and Memoranda for
Goldsmiths, Jewelers. 16mo, 0 50

Collis, A. G. High and Low Tension Switch-Gear Design 8vo, *3 50

---- Switchgear. (Installation Manuals Series.) 12mo, *0 50

Comstock, D. F., and Troland, L. T. The Nature
of Electricity and Matter 8vo, *2 00

Coombs, H. A. Gear Teeth. (Science Series No. 120.) 16mo, 0 50

Cooper, W. R. Primary Batteries 8vo, *4 00

Copperthwaite, W. C. Tunnel Shields 4to, *9 00

Corfield, W. H. Dwelling Houses. (Science Series No. 50.) 16mo, 0 50

---- Water and Water-Supply. (Science Series No. 17.) 16mo, 0 50

Cornwall, H. B. Manual of Blow-pipe Analysis 8vo, *2 50

Cowee, G. A. Practical Safety Methods and Devices 8vo, *3 00

Cowell, W. B. Pure Air, Ozone, and Water 12mo, *2 00

Craig, J. W., and Woodward, W. P. Questions and
Answers About Electrical Apparatus 12mo, leather, 1 50

Craig, T. Motion of a Solid in a Fuel. (Science
Series No. 49.) 16mo, 0 50

---- Wave and Vortex Motion. (Science Series No. 43.) 16mo, 0 50

Cramp, W. Continuous Current Machine Design 8vo, *2 50

Crehore, A. C. Mystery of Matter and Energy 8vo, 1 00

Creedy, F. Single Phase Commutator Motors 8vo, *2 00

Crocker, F. B. Electric Lighting. Two Volumes. 8vo,
Vol. I. The Generating Plant 3 00
Vol. II. Distributing Systems and Lamps

Crocker, F. B., and Arendt, M. Electric Motors 8vo, *2 50

Crocker, F. B., and W