Produced by Olaf Voss, Don Kretz, Juliet Sutherland, Charles Franks and the Online Distributed Proofreaders Team [Illustration] SCIENTIFIC AMERICAN SUPPLEMENT NO. 430 NEW YORK, MARCH 29, 1884 Scientific American Supplement. Vol. XVII, No. 430. Scientific American established 1845 Scientific American Supplement, $5 a year. Scientific American and Supplement, $7 a year. * * * * * TABLE OF CONTENTS. I. ENGINEERING, MECHANICS, ETC.--The Iron Industry In Brazil.--By Prof. P. FEHRAND.--Methods of obtaining iron.--Operation of the system.--Elaboration of the ore.--Setting up a forge.-- Selling price of iron The Steamer Churchill, built by Messrs. Hall, Russell & Co., for service at Natal.--With full page of illustrations Three-Way Tunnels Falconetti's Continuously Primed Siphon.--Manner of carrying a water course over a canal, river, or road.--With engraving The Weibel-Piccard System of Evaporating Liquids.-- 2 illustrations II. TECHNOLOGY.--Coal Gas as a Labor--saving Agent in Mechanical Trades.--By T. FLETCHER.--Gas as fuel.--Arrangement of burners for disinfection, for drying glue, albumen, etc.--Best burners. --Gas bars for furnaces, etc. Instantaneous Photography.--Several illustrations III. ELECTRICITY, MAGNETISM, ETC.--Electric Launches.--A paper read before the Society of Arts by A. RECKENZAUN, and discussion on the same.--Advantages of electromotive power.-- Cost of same.--Experimental electric launches First Experiments with the Electric Light.--Sir Humphry Davy's experiments in 1813,--With two engravings Electrical Grapnel for Submarine Cables and Torpedo Lines.-- 3 figures Hughes' New Magnetic Balance.--1 figure Apparatus for Measuring Small Resistances.--With engraving and diagram Terrestrial Magnetism.--Magnetism on railways.--Synchronous Seismology IV. ARCHITECTURE.--Adornments of the New Post Office at Leipzig.-- 2 engravings V. NATURAL HISTORY, ETC.--Comparison of Strength of Large and Small Animals.--By W. N. LOCKINGTON Oil in California VI. HORTICULTURE, BOTANY. ETC.--The Dodder.--A new parasitic plant.--With engraving Recent Botanical Investigations VII. MEDICINE, HYGIENE ETC.--Nutritive Value of Condiments.--By H. D. ABBOTT VIII. MISCELLANEOUS.--Mont St. Michel, Normandy.--With engraving * * * * * THE DODDER. The genus _Cuscuta_ contains quite a number of species which go under the common name of dodder, and which have the peculiarily of living as parasites upon other plants. Their habits are unfortunately too well known to cultivators, who justly dread their incursions among cultivated plants like flax, hops, etc.