230 
THE TELEGRAPH . 
it turns on a wooden pivot. This plan was suggested by Stroh, 
and is better than the old arrangement of a vertical wheel. 
Fig. 163. 
In the apparatus described above, the current acts directly 
on the inking system ; but when the line is very long, the 
Fig. 164. 
current received at the distant station would be too feeble to 
move the lever. In these cases certain apparatus called relays 
are resorted to, by which a delicately adjusted arrangement is 
made to close the circuit of a local battery that acts on the 
