68 
MR. W. H. BARLOW ON THE SPONTANEOUS ELECTRICAL CURRENTS 
First Day's Ohservations^ May \st, 1848. 
The positions of the earth connection were, — 
No. 1 wire. Derby and Willington, bearing S.W. 
No. 2 wire. Derby and Rugby, bearing S. 15° E. 
The path described by the two galvanometer needles is shown in figs. 1 and 2, and 
it will be seen that there is an obvious similitude throughout all their movements. 
Second Days Observations, May 3rd, 1848. 
The position of the earth connections were, — 
No. 1 wire. Derby and Willington, bearing S.W. 
No. 2 wire. Derby and Leicester, bearing S. 38° E. 
The movement of the galvanometers is shown at figs. 3 and 4. There is a partial 
similarity in the forenoon, but none* afterwards. 
Third Days Observations, May bth, 1848. 
Earth connections the same as in the last experiment. 
The paths of the galvanometers is shown at figs. 5 and 6. There is no similarity 
in the movement of the needles, excepting that the general march of both needles is 
from the left in the morning, towards the right in the afternoon. 
Fourth Days Observations, May 3th, 1848. 
The position of the earth connections were, — 
No. 1 wire. Derby and Willington, bearing S.W. 
No. 2 wire. Derby and Kegworth, bearing S. 62° E. 
The movement of the needles is shown at figs. 7 and 8. 
In this case we have a contrary direction of the current clearly marked and ren- 
dered more evident by the larger deflections which occurred on this day. 
These experiments are satisfactory as verifying the former observations made on 
this subject from time to time during the last twelve months. 
It should be mentioned that no part of the Rugby wire was disconnected in these 
experiments, but that the whole length of wire was in action, and therefore exposed 
to the same influences from atmospheric currents, induction, or thermo-electric 
action. There was no alteration whatever made in the wire excepting the change of 
position of one of its earth connections', and consequently the reversing of the direc- 
tion of the current in the wire, as compared with that of the Willington wire, cannot 
be attributed to any other cause. 
The question naturally presents itself, from whence do these currents arise ? 
On this subject an important fact was ascertained during the large deflections 
which occurred in September and October, namely, that spontaneous deflections of 
