RELIGHTING OF THE CARBON ARC. 225 
unable to find, with the data at hand, an explanation of the 
critical characteristic of the curves for the other cases. 
5. Critical characteristic as affected by arc length and 
previous current.—With a view to finding the influence of 
arc length and previous current on the critical characteristic 
of the curves just mentioned, further observations have 
been made in connection with case 3, in which the carbons 
are in the normal position and the battery connections 
remain unaltered during the interval between the break 
Fig. 5. 
: iy, 
ees 
ee 7 hy aad 
Arc length 0:-6mm. 
Potential difference between Carbons at make of circuit in Volts. 
60 z 
(0) ‘| 2 3 4 
Interval between break and make of circuit in Seconds. 
O—Sept. 2, 1908. 
