SCIENCE. 



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Illusions : 



A PSYCHOLOGICAL STUDY. 

 Intuition,' ' Pessimism,' etc. 

 price $1.50. 



By James Sully, author of ' Sensation and 

 International Scientific Series. i2mo, cloth, 



" The present volume takes a wide survey of the field of error, embracing in its view not only the illusions of 

 sense, dealt with in treaties on psychological optics, etc., but also other errors familiarly known as illusions, and 

 resembling the former in their structure and mode of origin." — From Preface. 



" This is not a technical work, but one of wide popular interest, in the principles and results of which every one 

 is concerned. The illusions of perception of the senses and of dreams are first considered, and then the author 

 passes to the illusions of introspection, errors of insight, illusions of memory, and illusions of belief. The work is a 

 noteworthy contribution to the original progress of thought, and may be relied upon as representing the present 

 state of knowledge on the important subject to which it is devoted." — Popular Science Monthly. 



" Mr. Sully's analysis of his whole subject leaves us at the close impressed with the ability of the writer's 

 statement. — Saticrday Review. 



For sale by all booksellers, or sent by mail, post-paid, on receipt of price. 



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SCIENCE 



A WEEKLY JOURNAL OF SCIENTIFIC PROGRESS. 



Vol. II, No. 60, 



- August 20, 1 881 



CONTENTS. 



International Electrical Exhibition (Edit.); Royal Astronomer (Edit.); Sea Mosses 

 (Edit.); Sea Mosses — Time and Place for Collecting, by A. B. Hervey ; Rotatory 

 Power of Commercial Glucose and Grape Sugar, by Professor W. H. Wiley ; 

 Unity of Nature, (concluded) by the Duke of Argyll ; Elements of Comet [6), i8i 

 Dr. D. Draper's Weekly Meteorological Report for New York City, Week Ending 

 August 13. 



WEBSTER, 



The following from Webster, page lir,4, shows 

 the value of the Illustrative Definitions in 



Webster's Unabridged Dictionary 



Subscription, Pour Dollars a Year. 



Single Numbers, Ten Cents. 



1, flyingjib; 2, jib; 3, fore-top-mast-stay sail; 

 4, fore-course; 5, foretop sai 1 ; 6, foretop-gallant 

 sail; 7, fore-royal ; 8, fore sky-sail; 9, fore-roy- 

 al studding sail; 10, foretop-gallant studding- 

 sail; 11, foretop-mast studding-sail; 12, main- 

 course; 13, maintopsail; 14, maintop-gallant 

 sail; 15, main-royal; 16, main sky-sail; 17, 

 main royal studding-sail; 18, main top-gallant 

 studding-sail; 19, maintop-mast studding sail; 

 20, mizzen-course ; 21, mizzen-top sail; 22, 

 mizzen-top-gallant sail; 23, mizzen-royal; 24, 

 mizzen sky-sail; 25, mizzen-spanker. 



The pictures in Webster under the 12 words. 

 Beef, Boiler, Castle, Column, Eye, Horse, 

 Moldings, Phrenology, Ravelin, Ships, 

 (pages 1104 and 1219) Steam engine, Tim- 

 bers, define 343 words and terms far better 

 than they could be defined in words. 



New Edition of WEBSTER, has 

 118,000 Words, 3000 Engravings, 

 4600 New Words and Meanings, 



Biographical Dictionary 



of over 9700 Names. 



Published by G.&C. MERR|AM,Springfield,Ma2* 



