OBSERVED IN THE WIRES OF THE ELECTRIC TELEGRAPH. 
65 
3rd. That exclusive of the irregular disturbances the currents flowed in a southerly- 
direction from about eight or nine a.m. until the evening, and in a northerly direction 
during the remainder of the twenty-four hours. 
The next experiments were made with a view to ascertain if any immediate rela- 
tion existed between the motion of the galvanometers and the daily variation of the 
horizontal magnetic needle. 
For this purpose I caused a temporary observatory to be erected in my garden at 
Derby (about a mile from the railway station, where the galvanometer experiments 
were made), and furnished it with a very delicate declinometer. 
On making observations with the two instruments, it became evident that, although 
generally that part of the day in which the currents flow southwards (that is, from 
eight or nine a.m. until the evening) the variation of the horizontal magnetic needle is 
westerly, and that during the night and early part of the morning (at which time the 
currents travel northwards) the variation is easterly; yet simultaneous observations 
showed no similarity in the path described by the magnetic needle and the galva- 
nometer. 
It had however been mentioned by Colonel Sabine, when my former paper on this 
subject was read, which described large deflections having occurred on the evening 
of the 19th of March, 1847, that unusual disturbances had been observed at the same 
time in the magnetic needle not only in England but abroad ; I therefore waited for 
an opportunity to repeat the experiments with the declinometer at a time when the 
telegraph needles were unusually deflected. 
On the 24th of September 1847, I was enabled partially to carry out this inten- 
tion ; and on the 27th I obtained a set of simultaneous observations on the galvano- 
meter and the magnetic needle, the galvanometer being attached to a wire having 
its earth connections at Derby and Rugby. 
These observations show unusual disturbances on both instruments on the days 
mentioned, particularly on the 24th, when it was excessive. 
From communications I have been favoured with, it appears that the deflections 
of the telegraph needles on the 24th of September were general throughout the 
kingdom. They were observed on the South Devon line and in Scotland, as well 
as on all the lines in this part of the country ; and it is worthy of remark, that all the 
reports of the telegraph clerks agree nearly in the time of the commencement of the 
disturbance, the earliest time stated being 1T35 a.m., and the latest noon. 
The 23rd of October was another day of strong deflections, and a partial register 
was kept of them in London by Mr. Hatcher. They were equally strong on the 
Midland line, and I have accounts of them as far as Newcastle. The 24th being 
Sunday, there was no register kept ; but they continued on the 25th, and were again 
registered by Mr. Hatcher in London, who has favoured me with his observations ; 
but beyond the fact of the unusual disturbance, they throw no additional light on 
this subject. 
MDCCCXLIX. 
K 
