#The Causes of the Contamination of Pit Air -- The Means of Preventing the Dangers resulting from the Contamination of Pit Air -- Calculating the Volume of Ventilating Current necessary to free Pit Air from Contamination -- Determination of the Resistance Opposed to the Passage of Air through the Pit -- Laws of Resistance and Formulae therefor -- Fluctuations in the Temperament or Specific Resistance of a Pit -- Means for Providing a Ventilating Current in the Pit -- Mechanical Ventilation -- Ventilators and Fans -- Determining the Theoretical, Initial, and True (Effective) Depression of the Centrifugal Fan -- New Types of Centrifugal Fan of Small Diameter and High Working Speed -- Utilising the Ventilating Current to the utmost Advantage and distributing the same through the Workings -- Artificially retarding the Ventilating Current -- Ventilating Preliminary Workings -- Blind Headings -- Separate Ventilation -- Supervision of Ventilation# -- INDEX. #HAULAGE AND WINDING APPLIANCES USED IN MINES.# By Carl VOLK. Translated from the German. Royal 8vo. With Six Plates and 148 Illustrations. 150 pp. Price 8s. 6d. net. (Post free, 9s. home; 9s. 3d. abroad.) #Contents.# Haulage Appliances -- Ropes -- Haulage Tubs and Tracks -- Cages and Winding Appliances -- Winding Engines for Vertical Shafts -- Winding without Ropes -- Haulage in Levels and Inclines -- The Working of Underground Engines -- Machinery for Downhill Haulage. #DENTAL METALLURGY.# #DENTAL METALLURGY: MANUAL FOR STUDENTS AND DENTISTS.# By A. B. GRIFFITHS, Ph.D. Demy 8vo. Thirty-six Illustrations. 200 pp. Price 7s. 6d. net. (Post free, 7s. 10d. home; 8s. abroad.) #Contents.# Introduction -- Physical Properties of the Metals -- Action of Certain Agents on Metals -- Alloys -- Action of Oral Bacteria on Alloys -- Theory and Varieties of Blowpipes -- Fluxes -- Furnaces and Appliances -- Heat and Temperature -- Gold -- Mercury -- Silver -- Iron -- Copper -- Zinc -- Magnesium -- Cadmium -- Tin -- Lead -- Aluminium -- Antimony -- Bismuth -- Palladium -- Platinum -- Iridium -- Nickel -- Practical Work -- Weights and Measures. #ENGINEERING, SMOKE PREVENTION AND METALLURGY.# (p. c26) #THE PREVENTION OF SMOKE.# Combined with the Economical Combustion of Fuel. By W. C. POPPLEWELL, M.Sc., A.M.Inst., C.E., Consulting Engineer. Forty-six Illustrations. 190 pp. Demy 8vo. Price 7s. 6d. net. (Post free, 7s. 10d. home; 8s. 3d. abroad.) #Contents#. Fuel and Combustion -- Hand Firing in Boiler Furnaces -- Stoking by Mechanical Means -- Powdered Fuel -- Gaseous Fuel -- Efficiency and Smoke Tests of Boilers -- Some Standard Smoke Trials -- The Legal Aspect of the Smoke Question -- The Best Means to be adopted for the Prevention of Smoke -- Index.