20 SCIENTIFIC BOOKS PUBLISHED BY 



Harrison s Mechanic s Tool-Book. 



12mo. Cloth. $1.50. 



MECHANIC S TOOL BOOK, with practical rules and suggestions, 

 for the use of Machinists, Iron Workers, and others. By W. B. 

 HAEEISON, Associate Editor of the &quot; American Artisan.&quot; Illustra 

 ted with 44 engravings. 



&quot; This work is specially adapted to meet the wants of Machinists and work 

 ers in iron generally. It is made up of the work-day experience of an intelli 

 gent and ingenious mechanic, who had the faculty of adapting tools to various 

 purposes. The practicability of his plans and suggestions are made apparent 

 even to the unpractised eye by a series of well-executed wood engravings.&quot; 

 Philadelphia Inquirer. 



Pope s Modern Practice of the Elec 

 tric Telegraph. 



Eighth Edition. 8vo. Cloth $2.00. 



A Hand-book for Electricians and Operators. By FBANK L. POPE. 

 Seventh edition. Rerised and enlarged, and fully illustrated. 



Extract from Letter of Prof. Morse. 



&quot; I have had time only cursorily to examine its contents, but this examina 

 tion has resulted in great gratification, especially at the fairness and unpre 

 judiced tone of your whole work. 



&quot; Your illustrated diagrams are admirable and beautifully executed. 



&quot; I think all your instructions in the use of the telegraph apparatus judi 

 cious and correct, and I most cordially wish you success.&quot; 



Extract from Letter ctf Prof. O. W. Hough, of the Dudley Observatory. 



&quot; There is no other work of this kind in the English language that con 

 tains in so small a compass so much practical information in the application 

 of galvanic electricity to telegraphy. It should be in the hands of every one 

 interested in telegraphy, or the use of Batteries for other purposes.&quot; 



Morse s Telegraphic Apparatus. 



Illustrated. 8vo. Cloth. $2.00. 



EXAMINATION OF THE TELEGRAPHIC APPARATUS 

 AND THE PROCESSES IN TELEGAPHY. By SAMUEL F. 

 B. MORSE, LL.D., United States Commissioner Paris Universal 

 Exposition, 1867. 



