18 , REPORT—1868. 
Exectriciry, MAGnNeErisM. 
On Bonelli’s Printing Telegraph. By W. Coox. 
The author remarked upon the simplicity, regularity, and economy of time which 
Bonelli’s system offers as compared with others. Independence of synchronic 
movement or elaborate clock-work, freedom from all delicacy in the mechanical 
detail, and the substitution of the most absolute simplicity in the place of that 
which, until now, demanded a special knowledge to keep the machines in working 
order, are among the practical advantages obtained; while, on the other hand, 
rapidity and certainty, never even hoped for, are ensured. The principal features 
of the new system are two tables in cast iron, placed inversely to each other at the 
corresponding stations, and each provided with a miniature railway, over which 
run two waggons, one carrying the type-set message, the other the paper, chemi- 
cally prepared with nitrate of manganese, and two combs, formed by the ex- 
tremities of the wires of the line, one of which touches the type at one station, 
while the other passes over the prepared paper at the other; a spring catch to each 
of the waggons setting them free to move by the closing of an electrical current. 
Neither on short circuit nor at a distance has the slightest difficulty in working 
the Bonelli machine been experienced, a well-considered system of counter-currents 
having completely annihilated the inconveniences which, from the time of Bain to 
the present moment, have been inevitable in electrochemical telegraphy. 
On a Printing Telegraph. By D. E. Hucues. 
This instrument requires but one-electrical wave for each letter, whereas for the 
“Morse” an average of four waves is required for each letter, and the dial instrament 
requires seven. There are twenty-eight keys, like the keys of a piano, each corre- 
sponding to a letter or mark—as (say) a full-stop or a number—at pleasure. When 
one of the keys corresponding to a letter is depressed, this brings a detent in contact 
with a pin corresponding to that letter on the circumference of a uniformly revolving 
type-wheel, stops it, and at the same time sends an electric wave to the distant 
station, which, by an electro-magnet detaching a similar detent, stops the same 
letter for the instant, and, by a revolving cam brought up, presses the paper against 
the type, the impression of which is thus taken at the distant station. The rising 
of the detent by the key rising to its place simultaneously stops the electric current, 
and each wheel again starts into motion at the same letter, as they had each been 
stopped exactly at the same letter; and so letter after letter is printed nearly as 
fast as the keys of a pianoforte can be moved. The chief mechanical feature of 
this machine is the almost mathematical synchronism of the two type-wheels, 
continuously revolving—one at the transmitting, the other at the distant receiving 
station—any little difference that may accidentally occur ges) corrected by the 
machine itself; this exact synchronism between the two type-wheels is absolutely 
necessary. Approximate synchronism is obtained by the adjustment of two vibrat- 
ing springs in unison—the perfect synchronism being obtained by a small correc- 
tion, produced, as each letter is printed, by the very act of printing. The type- 
wheel is either hastened or retitled, as may be required, to fitng the letter trul 
opposite the printing-pad. The means by which the machine corrects itself at eac 
letter, or at the commencement of work, is by means of a correcting cam—a solid 
wedge, pushed down into a similar hollow wedge—one on the driving part, the 
other on the arbour of the wheel. The paper to be printed on is coiled on a reel, 
and is drawn forward by the machine, and pressed up against the letter to be 
printed by the electric wave that brings the required letter or number to its place 
at the under side of the revolving wheel. .A special value in working submarine 
cables is claimed for this instrument, the following rates of speed having been 
obtained in different lengths :— 
Atlantic Cable... 0. ......... 2500 miles, 4 words per minute. 
Red Sea cable ............ 2000 ,, 6 5a 
” no See ee 1000 2?) 19 a 
” ” aravace © Mid) te PY are 500 ” 24 ” 
