C. V. WALKEE ON JMAGNETIC STOEMS AND EAETH-CDEEENTS, 
97 
nating at Ashford and Eamsgate; the third, on the short group from Ramsgate to 
Margate, is less delicate. I may mention that arrangements of this kind are general, the 
long cu’cuits being famished with the best instruments. This Table is a good specimen 
of the notes that are usually taken, and of the manner in which the returns are sent in. 
In the column headed “ Dmection,” the observers insert the letter to which the telegraph 
needles point; I have substituted for this the direction in which a derived current 
of positive electricity would be travelling when that letter was made. By N., I mean a 
positive current passing from the station that is more northerly to the one that is more 
southerly, and by S. vice versa. And in all cases, as well in this as in the Tables and 
diagrams that foUow, the magnetic north is referred to. The value of the deflections 
observed on the needles are in this Table expressed in very general terms. The word 
“hard over” means 45°, or thereabouts; “horizontal,” 80° or more, in fact as far over 
as it can well go. I have placed a copy of this Table in the hands of Professor Elias 
Loomis, as he had no continuous series like this m the collection of observations that 
he had published. It contains some of the details for which M. De la Rive inquired. 
This Table may be taken as correct as far as it goes. It contains many blank spaces, the 
observations having necessarily been discontinued from time to time. The changes of 
the needles from right-hand to left-hand deflections are gradual. One of my best 
observers says^ “ I have not at any time known the needles to return suddenly from their 
deflected position. I have frequently observed them to pass very quickly from one side 
to the other in a gradual manner, as though worked round by some slow-moving ma- 
chinerjq but never to drop suddenly. I have also observed the needles to partially right 
themselves, and then to be brought back again to quite as strong, and frequently much 
stronger deflected position.” The manner in which the change from a north to a south 
current is brought about is very remarkable ; it is evidently no drift of a “ circular 
magnetic storm,” so to speak, nor is it any kind of axial rotation. To all appearance 
the north current gradually fades away, and the south as gi’adually rises and increases in 
value. When a series of lines converge from various points of the horizon, the change 
of deflection on one instrument is accompanied by a change on all the others ; and 
this is the case throughout the district. And it has been observed that needles of the 
most active groups are a little less sluggish in these changes than are the needles of the 
less active groups. In the midst of storms the needles very frequently have periods of 
entire tranquility ; so, on the other hand, in the midst of calm the needles have periods 
of actmty, sometimes of a few minutes’ duration only, and then all is again still. The 
following are a few cases taken at random from many such : — 
1859, November 13, four slight deflections during the day. 
14, two slight deflections during the day. 
18, one slight deflection from 7.35 to 8 a.m. 
1860, January 15, one slight deflection from 9.10 to 9.23 p.m. 
30, one slight deflection. 
February 27, one slight deflection. 
April 21, one slight deflection. 
MDCCCLXI. p 
