6G 
MR. W. H. BARLOW ON THE SPONTANEOUS ELECTRICAL CURRENTS 
I have no magnetic observations on the 23rd, 24th, or 25th of October, but I have 
since learnt that an unusual magnetic disturbance occurred on these days, and there 
appears no doubt of the coincidence of these great disturbances in both instruments. 
On the three occasions mentioned, namely, the 19th of March, the 24th and 25th 
of September, and the 23rd, 24th and 25th of October, aurora was visible; and in 
every case which has come under my observation, the telegraph needles have been 
deflected whenever aurora has been visible. 
It only remains now to describe the experiments made to ascertain the line of 
direction in which the currents alternate, and it will serve to render this part of the 
subject more clear, to state in this place that, from numerous experiments, it appears 
that from whatever cause the currents are produced, the direction of the current at 
a given time in any wire depends on the relative positions of the earth connections, 
if the insulation is good, however circuitous may be the route of the wire itself. For 
example, the telegraph from Derby to Rugby, forty-nine miles in length, proceeds 
for ten miles about S.E. by E. to Kegworth ; then for nineteen miles it takes a S.E. 
direction to Leicester, and the remaining twenty miles to Rugby is about S.S.W. 
Having one earth connection at Derby, if the other be made at Rugby, the bearing 
of which place from Derby is S. 15° E. ; the deflections accord with those of the wire 
to Birmingham, bearing S. 29° W. ; but if the earth connection of the Rugby wire be 
changed from Rugby to Kegworth, the bearing of which from Derby is S. 62° E., the 
deflections produced are in the contrary direction to those of the Birmingham Mure. 
I do not consider that this fact in itself proves that the currents are generated in 
the earth, for they might arise from other causes, and yet exhibit the same result. 
I only mention the fact in this place to facilitate the consideration of the direction 
in which the cui’rents alternate, and to indicate that when the direction of the cur- 
rent between any two places is described, it is not meant that the wire is laid in a 
direct line between the two points, but that the earth connections are so placed. 
Referring the direction of deflection in every case to those produced by the 
Birmingham wire, and denoting those which accord with it by the sign -|-, and those 
which exhibit a contrary deflection — , the results of the experiments on direction 
were as follows : — 
Derby to Willington, bearing . 
Derby to Birmingham, bearing . 
Derby to Rugby, bearing . . . 
Derby to Leicester, bearing . . 
S.W. H- 
S. 29° W. + 
S. 15° E. + 
Derby to Loughborough, bearing 
Derby to Kegworth, bearing 
S. 38° E. -f- - 
S. 50° E. doubtful. 
Derby to Nottingham, bearing . 
Derby to Lincoln, bearing . . 
Derby to Chesterfield, bearing . 
Derby to Normanton, bearing . 
S. 62° E. — 
N. 80° E. - 
N. 60° E. — 
N. 5° E. - 
30 _ 
