[Illustration] SCIENTIFIC AMERICAN SUPPLEMENT NO. 795 NEW YORK, March 28, 1891. Scientific American Supplement. Vol. XXXI., No. 795. Scientific American established 1845 Scientific American Supplement, $5 a year. Scientific American and Supplement, $7 a year. * * * * * TABLE OF CONTENTS. I. AVICULTURE.--The Effect on Fowls of Nitrogenous and Carbonaceous Rations.--A very valuable report upon the effects of different diet on chickens, with tables of data.--1 illustration II. BIOGRAPHY.--N.F. Burnham and his Life Work.--By W.H. BURNHAM. --The life of one of the earliest turbine wheel manufacturers, an inventor of turbine wheels and auxiliary machinery. --1 illustration III. BOTANY.--The Source of Chinese Ginger.--An identification of a long unknown plant IV. CIVIL ENGINEERING.--A Railway through the Andes.--An interesting enterprise now in progress in South America, with maps.--2 illustrations Chicago as a Seaport.--Proposed connection of Chicago with the waters of the Mississippi River, thereby placing it in water communication with the sea.--2 illustrations Floating Elevator and Spoil Distributor.--A machine for removing dredged material from barges, as employed on the Baltic Sea Canal Works.--10 illustrations V. ELECTRICITY.--Alternate Current Condensers.--A valuable review of the difficulties of constructing these condensers.--An important contribution to the subject.--1 illustration Electricity in Transitu.--From Plenum to Vacuum.--By Prof. WILLIAM CROOKES.--Continuation of this important lecture with profuse illustrations of experiments.--14 illustrations The Telegraphic Communication between Great Britain, Europe, America, and the East.--By GEORGE WALTER NIVEN.-- The engineering aspects of electricity.--The world's cables and connections.--2 illustrations VI. HORTICULTURE.--Herbaceous Grafting.--A hitherto little practiced and successful method of treating herbs, with curious results VII. MECHANICAL ENGINEERING.--Improved Cold Iron Saw.--The "Demon" cold saw for cutting Iron.--Its capacity and general principles.--1 illustration VIII. MEDICINE AND HYGIENE.--How to Prevent Hay Fever.--By ALEXANDER RIXA.--A systematic treatment of this very troublesome complaint, with a special prescription and other treatment. IX. MISCELLANEOUS.--The Business End of the American Newspaper.--By A.H. SIEGFRIED.--A graphic presentation of the technique of the newspaper office, circulation of the American papers, methods of printing, etc. The New Labor Exchange at Paris.--A new establishment, long demanded by the laboring population of Paris.--Its scope and prospects.--2 illustrations