152 
MR. DANIELL ON VOLTAIC COMBINATIONS. 
The deviation of No. 1. was 60° E. 
No. 2. — 35 E. 
and No. 2. wavered a little. 
Extra connection again halved, or thirteen feet four inches. 
The deviation of No. 1. was 40° E. 
No. 2. — 30 E. 
and No. 2. began to oscillate. 
Extra connection once more halved, or six feet eight inches. 
The deviation of No. 1. was 28° E. 
and No. 2. oscillated from E. and W. very strongly. 
The extra connection was then made by only four inches of the same wire : 
The deviation of No. 1. was 15° E. 
No. 2. — 30 W. 
and the needle was only slightly unsteady. 
The extra connection was then entirely removed, and 
The deviation of No. 1. was 80° E. 
No. 2. — 45 E. 
Now with regard to the main battery current, when the extra connection was 
wholly removed, the whole passed through No. 1. galvanometer with a certain resist- 
ance, and was measured by its deflection 80° : when the long wire was added, a por- 
tion was diverted into the new channel, and was measured by the decline of the 
needle to /0°- As the length of the extra wire was shortened, the resistance of this 
passage decreased, and more and more of the current was diverted from the galvano- 
meter till the deflection of the needle only amounted to 1 5°, and nearly the whole 
passed through the extra wire. 
The effect of these varying resistances upon the secondary current I think I can 
explain with the help of the annexed diagram. Let the circles 1, 2, 3, 4, 5, (fig. 2.) 
represent sections of the five battery cells, and the lines between 3 and 4, 4 and 5, 
5 and 1, and 1 and 2, with the arrow heads, the short wires between the zinc of each 
cell and the copper of the next, with the direction of that conventional current which 
is supposed to flow from one to the other. Let ABC represent the long wire of a 
galvanometer, or the electrodes of a voltameter through which the circuit is com- 
pleted between 2 and 3, and by which the current is resisted. When a secondary 
connection is formed by the wire abed , between the zinc e and the copper g of the 
cell No. 1, a portion of the main current, which tends to pass through the electrolyte 
to the copper at f, being obstructed in this direction, passes to g, and completes its 
circuit through the wire abed, and the diverted current obviously will flow in the 
same direction as the main current, or from the copper through the wire to the zinc. 
But if, instead of a resisting communication, the primary circuit be completed be- 
tween 2 and 3 by a short wire, as between the other cells, and as represented at 
