[Illustration] SCIENTIFIC AMERICAN SUPPLEMENT NO. 601 NEW YORK, JULY 9, 1887 Scientific American Supplement. Vol. XXIV, No. 601. Scientific American established 1845 Scientific American Supplement, $5 a year. Scientific American and Supplement, $7 a year. * * * * * TABLE OF CONTENTS. I. ASTRONOMY.--A Star Finder.--A simple apparatus that can be constructed by any mechanic.--1 illustration. Photographic Study of Stellar Spectra, Harvard College Observatory. --First annual report of the Henry Draper memorial observations. --Review of the work by Prof. EDWARD C. PICKERING. II. BIOLOGY.--Sponges.--The growth and life history of sponges.--Report of a recent lecture at the London Royal Institution by Dr. R. VON LEDENFELD. III. ELECTRICITY.--Phenomena of Alternating Currents.--By Prof. ELIHU THOMSON.--16 illustrations. IV. ENGINEERING.--An English Car Coupling.--Description of an English automatic coupling.--2 illustrations. A New Process of Casting Iron and other Metals upon Lace, Embroideries, Fern Leaves, and other Combustible Materials. --By A.E. OUTERBRIDGE, JR.--A new and eminently practical process of producing ornamental castings.--4 illustrations. Bricks and Brick Work.--By Prof. T. ROGER SMITH, F.R.I.B.A. --The history and technical review of this subject.--A most remarkable contribution to the engineering of architecture. Link Belting.--By CHARLES A. SCHIEREN.--An interesting and practical paper on leather belting made of links. --9 illustrations. Recent Progress in Gas Engineering.--A lecture by Mr. A. MACPHERSON, of Kirkcaldy, reviewing the last improvements in this branch. V. MISCELLANEOUS.--Herbet's Tepid Douche.--Apparatus in use for bathing soldiers in the French barracks.--1 illustration. Kent's Torsion Balance.--A new type of balance, involving torsional suspension instead of knife edges.--5 illustrations. Preservative Liquid.--Note on preservation of organic substances. The Falls of Gairsoppa.--The great Indian falls, higher than Niagara.--2 illustrations. The New British Coinage and Jubilee Medal.--Illustrations and descriptions of the new pieces.--8 illustrations. The Winner of the Derby.--Portrait and description of Merry Hampton. VI. NAVAL ENGINEERING.--The Falke Type Torpedo Boat.--The fastest type of British torpedo boat, constructed by Messrs. Yarrow & Co.--1 illustration. The German Navy.--The New Gunboat Eber.--A description of a late accession to the German navy.--1 illustration. VII. ORDNANCE AND GUNNERY.--Magazine Rifles.--Continuation of this important article, including the Chaffee-Reece, Kropatschek, and other magazine guns.--3 illustrations.