Produced by Huub Bakker, Juliet Sutherland and the Online Distributed Proofreading Team at http://www.pgdp.net [Illustration] SCIENTIFIC AMERICAN SUPPLEMENT NO. 647 NEW YORK, MAY 26, 1888 Scientific American Supplement. Vol. XXV., No. 647. Scientific American established 1845 Scientific American Supplement, $5 a year. Scientific American and Supplement, $7 a year. * * * * * TABLE OF CONTENTS. PAGE. I. ARCHITECTURE.--Elements of Architectural Design.--By H. H. Statham.--Continuation of this important contribution to building art, Gothic, Roman, Romanesque, and Mediaeval architecture compared.--26 illustrations. 10339 The Evolution of the Modern Mill.--By C. J. H. Woodbury.--Sibley College lecture treating of the buildings for mills. 10329 II. CHEMISTRY.--An Automatic Still.--By T. Maben.--An improved apparatus for making distilled water.--1 illustration. 10335 Testing Indigo Dyes.--Simple and practical chemical tests of indigo products. 10342 III. CIVIL ENGINEERING.--Railway Bridge at Lachine.--Great steel bridge across the St. Lawrence near Montreal.--2 illustrations. 10333 IV. ELECTRICITY.--Influence Machines.--By Mr. James Wimshurst.--A London Royal Institution lecture, of great value as giving a full account of the recent forms of generators of static electricity.--14 illustrations. 10327 V. HYGIENE.--The Care of the Eyes.--By Prof. David Webster, M.D.--A short and thoroughly practical paper on the all important subject of preservation of sight. 10341 VI. MECHANICAL ENGINEERING.--Economy Trials of a Non-condensing Steam Engine.--By Mr. P. W. Winans, M.I.C.E.--Interesting notes on testing steam engines. 10331 The Mechanical Equivalent of Heat.--By Prof. De Volson Wood.--A review of Mr. Hanssen's recent paper, with interesting discussion of the problem. 10331 VII. METEOROLOGY.--The Meteorological Station on Mt. Santis.--A new observatory recently erected in Switzerland, at an elevation of 8,202 feet above the sea.--1 illustration. 10341 VIII. NAVAL ENGINEERING.--Improved Screw Propeller.--Mr. B. Dickinson's new propeller.--Its form and peculiarities and results.--4 illustrations. 10333 IX. PHOTOGRAPHY.--Manufacture of Photographic Sensitive Plates.--Description of a factory recently erected for manufacturing dry plates.--The arrangement of rooms, machinery, and process.--10 illustrations. 10336