Produced by Olaf Voss, Don Kretz, Juliet Sutherland, and the Online Distributed Proofreading Team SCIENTIFIC AMERICAN SUPPLEMENT NO. 299 NEW YORK, SEPTEMBER 24, 1881 Scientific American Supplement. Vol. XII, No. 299. Scientific American established 1845 Scientific American Supplement, $5 a year. Scientific American and Supplement, $7 a year. [Illustration] * * * * * TABLE OF CONTENTS. I. ENGINEERING AND MECHANICS.--On the Progress and development of the Marine Engine.--Marine engines.--The marine boiler.--Steel boilers.--Corrosion of boilers.--How the marine engine may be improved.--Consumption of fuel.--Evaporative efficiency of marine locomotive boilers.--Screw propellers Steam Ferry Boats of the Port of Marseilles.--2 figures.-- Transverse and longitudinal sections Opening of a New English Dock. 1 figure Improved Grain Elevator. 1 figure Improved Dredger. 1 figure.--Single bucket dipper dredger Railway Alarm Whistle Furnace for the Manufacture of Sulphide of Carbon. 1 figure Brouardel's Dry Inscribing Manometer. 1 figure.--Gas indication of manometer Centrifugal Apparatus for Casting Metals. 4 figures.--Centrifugal metal moulding apparatus Apparatus for the Manufacture of Wood Pulp. 2 figures.--Dresel's wood pulp apparatus Recent Progress of Industrial Science.--Presidential address, Convention of Mechanical Engineers The Hoboken Drainage Problem II. TECHNOLOGY AND CHEMISTRY--On some Recent Improvements in Lead Processes. By NORMAN C. COOKSON Apparatus Used in Berlin for the Preparation of Gelatine Plates.-- I. Mixing apparatus.--II. Digestive apparatus.--III. Triturating apparatus--IV. Washing apparatus--3 figures How To Make Emulsions In Hot Weather. By A. L. HENDERSON The Distillation and Rectification of Alcohols by the Rational Use of Low Temperatures. By RAOUL PICTET.--1 figure.--Pictet's apparatus for the rectification of alcohol by cold The Removal of Noxious Vapors from Roasting Furnace Gases New Gas Exhauster. 1 figure Advance in the Price of Glycerine Analysis of Oils or Mixtures of Oils Used for Lubricating Purposes Nitrate of Amyl III. ELECTRICITY, ETC.--The Electric Light in Earnock Colliery Lightning and Telephone Wires Conditions of Flames Under the Influence of Electricity The Electric Stop-Motion in the Cotton Mill Electrolytic Determinations and Separations. By ALEX, and M. A. VON REIS.--Determination of cobalt.--Nickel--Iron.--Zinc.-- Manganese.--Bismuth.--Lead.--Copper.--Cadmium.--Tin.--Antimony.-- Arsenic.--Separation of iron from manganese.--Iron from Aluminum IV. MEDICINE, SURGERY, ETC.--Treatment of Acute Rheumatism. By ALFRED M. STILLE, M.D. Method in Madness