78 On the Municipal Electric Telegraph, 
. * 
_ Asingle Alarm Circuit may include a number of Alarm Sta 
tions. In all of these, in which the conditions are similar, the 
blows upon the bell should be synchronous. No matter how 
widely scattered over a City, the Signals would be struck.on the 
different bells practically at the same moment of time. Differ 
ences however in size, friction, proportion, would always exist, 
sufficient to make a slight difference in the instant of striking 
between a number of bells. Even if this were not so, differ 
ence in distance would cause the sound of one bell to reach the 
ear before another. Hence District Signals are always distit- 
guished by listening to the sound of a single bell. The effect of 
the District Key-board is to strike in succession the bells of dif 
ferent. Circuits. The interval in sound, however, thus occasioned, 
would not be so great as that produced by distance in bells of the 
- same Circuit. 
therefore in resistance to 44 miles of Circuit, which gives a total 
resistance of eight miles of 
the Battery must act, 
purposes, it is necessary that there s| 
of the bell ringer, communicating. w 
many accounts be desirable. 
The operation of the System has been shown in its detached 
parts. It will now be illustrated consecutively through all 
stages.. A fire having broken out in the neighborhood of 
its 
the 
ts) No. 8 wire, through which 
