SCIENTIFIC HOOKS FUBLISHED BY 
Harrison’s Mechanic’s Tool-Book. 
12mo. Cloth. $1.50. 
MECHANIC’S TOOL BOOK, with practical rules and snggestions, 
for the use of Machinists, Iron Workera, and others. By W. B. 
Harhison, Associate Editor o£ the “ American Artisan. Illustra- 
ted vrith 44 engravings. 
>■ 'phis 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 plane and suggeetione are made apparent 
evcn to the unpractised eye by a series of well-executed wood engravings. 
Philadelphia Inquirer. 
Pope’s Modern Practice of the Elec 
tric Telegraph. 
Eigktli Edition. 8vo. Cloth $2.00. 
A Hand-book for Electricians and Operators. By Fbakk L. Pope. 
Seventh edition. Bevised and enlarged, and fully illustrated. 
Extract from Letter of Prof. Morse. 
“ I have had time only cursorily to examine its contents, but this examma- 
tion has resulted in great gratification, especially at the faimess and nnpre- 
judiced tone of your whole work. 
“ Your illustrated diagrams are admirable and beautifully executed. 
“ I think all your instructions in the use of the telegraph apparatus judi- 
cious and correct, and X most oordially wish you success. 
Exlract from Letter of Prof. Q. W. Hough, of the Ihidley Observatory. 
“ There i» no other Work of this kind in the English language that con- 
tains in so small a compass so rnuch practical Information in the application 
of galranic electricity to telegraphy. It should be in the hands of ^ every one 
interested in telegraphy, or the use of Batteries for other purposes. 
Morse’s Telegraphie Apparatus. 
Illustrated. Bvo. Cloth. $2.00. 
EXAM1NATION OE THE TELEGBAPHIC APPABATUS 
AND THE PEOCESSES IN TELEGAPHY. By Samuel F. 
B. Moese, LL.D., United States Commissioner Paris Universal 
Exposition, 1867.