228 
THE TELEGRAPH 
ing to be written down at once by the clerk, introduce two 
sources of error. 
In some apparatus the silk fibres are suppressed by making 
the siphon move directly with the coil (fig. 161). Thus the 
difficulty of electrifying is removed, and the pressure of the 
atmosphere suffices to give a very distinct line on the paper, if 
the point of the siphon has been carefully prepared so as not 
to stick in the paper. The 
latter may, moreover, be 
covered with soapy matter to 
make it glide more smoothly 
under the siphon. 
Morse's Apparatus. — As 
Morse’s apparatus has been 
adopted by various European 
States, and by the American 
telegraph companies, it has 
more than any other exercised 
the ingenuity of mechanicians 
and inventors. Many im¬ 
provements have been made in 
it, and a large yet interesting 
volume might be written on 
this one subject. We shall 
however here confine our 
attention to the apparatus 
now used in overhead and sub¬ 
marine lines, and to the most improved forms of the me¬ 
chanism. 
Vail’s apparatus indented a slip of paper by a style with the 
well-known signals of the Morse code. All the apparatus that 
are now used print the signals with ink by means of the 
arrangement shown in fig. 162, where M is the manipulator, 
and L the line extending from one office to the other. The 
line is connected with an electro-magnet n. A lever, turning 
on the pivot a, is attached to the soft-iron armature a of the 
electro-magnet, and terminates in a little ink-wheel, b, that dips 
into a vessel of ink b. If the slip of paper p be continually 
passing in the direction shown by the arrows ; then a depression 
of the key m will connect the battery c z with the line at m, 
