ME. C. V. WALKEE ON MAONETIC STOEMS AND EAETH-CUEEENTS. 
93 
each on the other, and without reference to the route' pursued by the telegraph wire 
itself in its course from station to station ; and deduced from his observations that “ the 
direction in which the currents travel will be between S. 28° W. and S. 75° W.; and 
apparently strongest when the earth-connexions are N.E. and S.W.” The great inte- 
rest attached to the fact that the direction of the current depends on the relative posi- 
tions of the earth-connexions, and not on the direction of the wire itself, induced him 
to make further observations, which confirmed that view. They were made on May 1, 
2, 3, and 8, 1848. It was further ascertained that disturbances had been noticed on 
the short line of telegraph that was led entirely under ground from the Strand to Nine 
Elms. Taking this in connexion with the infiuence of the relative position of the earth- 
connexions, he continues, “ The most probable explanation appears to be that the cur- 
rents are terrestrial, of which a portion is conveyed along the wire, and rendered visible 
by the multiplying action of the coil of the galvanometer.” I refer particularly to this 
communication, because the two facts with which we have to deal — that currents are 
found travelling in the earth, and that a portion of such currents comes under our notice in 
the form of a derived current — are at the basis of all further inquiries into their nature. 
I have mentioned that the disturbances ceased to attract om’ notice after the close of 
the year 1848. Feeble deflections, it is true, were occasionally observed, but they were 
practically disregarded, as they were not of sufficient magnitude to interfere with tele- 
graphic operations. Our attention began again to be called forcibly to them about the 
close of the year 1856; and instructions were again issued to take notes and make a 
weekly return to me. The result is that I have a large accumulation of observations, 
commencing in April 1857 and continuing to the present date. It is not my intention to 
discuss these returns, nor to extract from them the dates of great disturbances. The 
fact that earth-currents, disturbed magnetometers, and aurorae are part of the same 
phenomenon, is too well established to require cases in point. 
The most remarkable magnetic storm on record, at least since lines of telegraph have 
existed, is that' which occurred in the autumn of 1859, commencing on August 27, and 
continuing until September 6. All the concurrent phenomena were manifested in a 
very exalted degree, and attracted the attention of observers in both hemispheres. Dis- 
turbances were conspicuous in Australia, as they were in Europe and America. Auroral 
fight was seen in latitudes as low as 20°, 18°, and 13° 18'. A series of five articles will 
be found in ‘The American Journal of Science and Arts’ (vol. xxviii. pp. 385 to 408; 
vol. xxix. pp. 92 to 97, 249 to 266, 386 to 399; and vol. xxx. pp. 79 to 89, being the 
numbers issued in November 1859, and in January, March, May, and July 1860). To 
the last of these the name of Professor Elias Loomis is attached; and the other four^, 
I believe, passed through his hands. 
The ninety-three pages referred to are enriched with a large collection of reports from 
* Since the above Tvas written, the November Number (1860) of Silliman’s Journal has appeared, with 
a sixth article of twenty-two pages (pp. 3 to 25) ; and the July Number (1861) with a seventh of fourteen 
pages (pp. 1 to 14). 
