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POPULAR SCIENCE REVIEW. 
far greater amount of accuracy is therefore attained by the 
recording apparatus than by any system of transient signals. 
The simplest printing telegraph is that of Professor Morse, 
of America. The alphabet consists of dots and dashes, and 
though purely conventional, is easily learned. It has been 
altered from time to time, in order that accidental irregu- 
larities in the distance between the dots and dashes shall not 
transform one important word into another; and although 
England at one time possessed an alphabet better suited to 
our own language, it was found necessary, on the establish- 
ment of direct communication with continental cities, to fall 
in with the system in use abroad, and the same characters are 
now adopted throughout the whole of the old world. 
THE MORSE ALPHABET. 
The Morse apparatus has been adopted almost univer- 
sally. It is sufficiently simple to be worked by any lad of 
ordinary capacity, does not readily get out of order, and if 
deranged, can be set right with perfect ease. The dots and 
dashes, or e( marks, - ” as they are called, are embossed by a 
steel tracer or pencil upon a ribbon of paper, drawn forward 
at a uniform speed by clock-work ; or written in colour upon 
the paper, by its being raised into contact with a small thin 
disk, covered with a peculiar ink. The latter arrangement 
produces more legible characters and requires less mechanical 
force than the embossing process, but needs a little more 
care. 
The arrangement by which the electric current causes the 
pencil to touch and recede from the paper, so as to mark it, 
is this : — 
In the upper roller of the pair by which the paper ribbon 
is carried forward is a groove; under the rollers is a lever, 
pivoted at its centre, carrying at one end the pencil or style, 
and at the other end a piece of iron, which forms the armature 
of an electro-magnet or horseshoe-shaped bar of iron, covered 
