114 Wire, crossing a river on a. 121 Wool, purifying. 114 Zinc roofs (4). 123 * * * * * TABLE OF CONTENTS OF THE SCIENTIFIC AMERICAN SUPPLEMENT, No. 60, For the Week ending February 24, 1877. I. ENGINEERING AND MECHANICS.--Artificial Production of Ice by Steam Power--The American Roller Skate Rink, Paris, 1 engraving.--The Little Basses Light House, 4 figures.--The Souter Point Electric Light.--On the Minute Measurements of Modern Science, by ALFRED MAYER.--Method of Measuring by Means of the Micrometer Screw furnished with the Contact Level; Method of Electric Contact Applied to Measurements with the Micrometer Screw, 2 engravings.--Abstracts from Report of the Boston Society of Civil Engineers on the Metric System.--New Turret Musical and Chiming Clock for the Bombay University, with 1 page of engravings.--Water Gas and its advantages, by GEO. S. DWIGHT.--Brattice Cloths in Mines.--Eight Horse Power Portable Steam Engine, with dimensions, particulars, and 1 page of engravings.--Clyde Ship Building and Marine Engineering in 1876.--Four Masted Ships.--New Bridges at and near New York city.--The Sutro Tunnel.--Independent Car Wheels.--Passenger Travel, New York city. II.--TECHNOLOGY.--Design for Iron Stairway, and Iron Grilles, with 3 engravings.--The Process of Micro-photography used in the Army Medical Department.--Direct Positives for Enlarging.--A Monster Barometer.--Architectural Science, Carpentry Queries and Replies.--The Carpet Manufactures of Philadelphia. How the Centre Selvage is Formed, 3 figures.--Glass of the Ancients.--On the Preservation of Meat; a resume of the various methods now practiced.--California Pisciculture.--Savelle's System of Distillation, 2 engravings.--New Bromine Still, by W. ARVINE, 1 engraving.--The Phoenix Steam Brewery, New York.--French Cognac Distillation, 1 engraving.--Schwartz's Sugar Refinery, London. General description of the establishment.--Vienna Bread and Coffee.--How Pictorial Crystals are Produced and Exhibited. III. LESSONS IN MECHANICAL DRAWING. New Series. By Professor C.W. MACCORD; with several engravings. IV. ELECTRICITY, LIGHT, HEAT, SOUND, ETC.--Magnetic Action of Rotatory Conductors.--The Sensation of Sound.--Sympathetic Vibration of Pendulums.--Protection from Lightning.--Musical Tones, photograph of. V. MEDICINE, HYGIENE, ETC.--On the Treatment of Typhoid Fevers. By ALFRED L. LOOMIS, M.D.--Hydrophobia Cured by Oxygen.--The efficacy of Lymph, by M. HILLER.--Success of Chloral Hydrate for Scalds and Burns.--Uses of Cyanide of Zinc.--Dr. Brown-Sequard on Nerve Disease. VI. MISCELLANEOUS.--Geological Notes.--A Geological Congress.--The last Polar Expedition.--Old Men of Science.--Pre-glacial Men.--Post-glacial period, Esthonia.--Northern Pacific Formations.