.G. Mathiot on the Atlantic Cable. 163 
‘as a wire having a solid section of 185,000 sq. ft.) in which the - 
resistance exterior to the battery may be considered as nothing, 
and the whole resistance to the generation of the electricity as 
being only that which lies within the battery: now taking Ohm’s 
formula for the electric current in which Z represents the 
R+? 
electromotive force of the chemical affinity, # the resistance to 
conduction due to the materials of the battery, and r the resist- 
ance of the conductor which completes the circuit by connecting 
the poles of the battery, and considering the effect of multiplying 
n 
: nR-+-r 
being indefinitely decreased by diminution of the length of the 
conductor, or by increase in its solid section, which are the con- 
ditions that obtain while the cable is receiving its static charge, 
we may consjder it as =0, and remove it from the equation, and 
ae | 
the number of the elements we have , and ing 7 as 
then we have a eoel in which it is evident a train of batteries 
in the conditions which obtain at the first moments of contact 
with the cable, can generate no more electricity than a single 
cell attached to the same conductor. It is here evident that the 
facts arrived at by Mr. Clark, so far from being a cause of won- 
derment, are but what the circumstances should have suggested, 
suggested by M. Melloni; much less do they indicate that a 
diminution of the size of the battery plates would hasten the 
cant, and as Sis constant, 7’ will fall enormously, as h 
before shown for another purpose ; now when the terminals of 
4 compound battery, are connected with a stout wire, it is known 
that the tension falls to that of a single pair of plates, it 1s there- 
fore evident that contact of the battery, with a large inductric 
Surface, is equivalent to connecting with a non-resisting conduc- 
tor. In this state of the battery it is evident that the electricity 
can be conveyed into the ot a only as fast as the batte 
can admit of the diffusion within, or bring the electricity to the 
terminals, in which case, as has before been shown, many pairs 
can generate no more electricity than a single pair, and conse- 
quently the tension will be below the maximum of a single pair, 
