70 On the Municipal Electric Telegraph, 
rangement, is an apparatus identical with one figured in Cooke 
and Wheatstone’s English patent of 1837, to which I take pleas 
ure in referring it. ; 
Switch is provided to disconnect the Alarm of any Circuit, whet 
the Register is used for continued communication. The Alarms 
connected with the different Circuits are provided with bells of 
different tone, so that it is immediately perceived, by the sound, 
from which circuit any Signal proceeds. é 
It is often desirable to send a communication, back to the Sig- 
nal Stations for purposes of police, or, it may be, to inform an off 
cer of the Fire Department of the number of the Station from 
. 
which an Alarm of Fire has been signalized. For these and similat 
be used for signalizing back to the Stations in the manner just 
described. For the 
over six miles, twelve pairs of the Odds and Ends battery of 
Smee, as constructed by Davis,* should be amply snfficient 
at least with the open circuit. Asa fact of general interest 10 
each Signal Cirenit. For this purpose a Daniel’s battery of get 
sibly an Odds and Ends battery of twelve pairs may be applied. . 
* Davis's Manual of Magnetism, 2nd edition, p. 56. 
