MAGNETISM AND ELECTRICITY. ia. 
taking a wide cylinder of paper consisting of a very wide strip wound 
round an axis, and cutting this on a turning lathe into short cylinders of 
equal diameter, and of a height equal to the width of the strip. One of 
these cylinder strips is to be placed in the proper part of the machine, the 
extremity unwound and then wrapped round a second cylinder, the 
unwound portion passing by the ink points. The cylinders of paper are 
turned by clock-work. fig. 41 exhibits the entire machinery in longitudinal 
section ; jig. 42 is the apparatus from above. Thirty different symbols are 
obtained by the varying positions of points ; of these twenty-two are letters 
and ten numeral signs, the letters c, q, u, 2, y, being omitted, while ch and 
sch are added. The figures 0 and 9 are expressed by the similarly shaped 
letters o and g. One high point indicates 7, one low e; two high n, two 
low r; three high m, three low o; four high h, four low ch: d is indicated 
een CDV es Per by . sie; @ by We by res o by 5; % by ..°5 byes 
Bey sarees Scie ay . eS hye tes ban oto Swe By ed 5s bytes IKOF 
ime Munmerdis 1 isindicated™ by 2by ons ses BS by we get; 4 bys ee; 
5S by*.e-;6by.°..;7by.-*-;8 by-..° Instead of points on a strip 
of paper, the signals may be made by the higher and lower tones, differing 
by about a sixth, of two metal or glass bells. It is evident that the same 
magnetic bars cannot write and strike simultaneously, on account of 
possessing too little power. In the neighborhood of the signal magnets are 
small magnets separated from them, and so placed as to bring back the 
former to their original position after striking; this renders it possible to 
make the signs with great rapidity (five times in a second). Small bells 
are used in this telegraph as in the last, to call the attention of the observer 
at the station whither the message is to be sent. In conclusion, pl. 22, fig. 42, 
represents the upper view, and fig. 41 the longitudinal section of a table 
standing on the floor of the room, and containing all the apparatus. The 
circuit wires, the ends of the multipller, and two conductors from the 
mercury vessel of the inductor, meet, as shown in fig. 42, in the centre of 
the table, where they pass into eight holes filled with mercury, made in a 
wooden cylinder. Upon the different connexions of these mercury holes 
the direction of the current depends. As the balance moves from right to 
left, or the reverse, one or the other signal marker is deflected, thus producing 
a higher or lower point (or tone). As long as the intervals of time 
between the single signs are equal these all belong to the same group. 
Different groups are separated by a longer pause, producing a longer 
interspace. 
The simplest of all telegraphs, and the one best adapted to the practical 
purpose of communicating intelligence from one part of a country to 
another, is unquestionably the one used in the United States, and known as 
Morse’s telegraph. A single wire only is here employed, which passes 
from the transmitting station to the receiving, and is there wound round an 
electro-magnet in the form of a horse-shoe. A plate of soft iron attached 
to one end of a lever is situated immediately above the extremities of the 
horse-shoe ; the other extremity of the lever carries a point. The strips of 
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