G. B. Prescott on the Aurora of 1859. 93 
cups Grove, with the line well insulated, will decompose the 
salts, and uniting with the iron stylus, leave a bright blue mark 
upon the paper, at a distance of 230 miles. 
The positive pole only produces a colored mark; .the negative 
bleaches the paper. 
hen there is no electric current upon the wires, the pen 
leaves no impression upon the paper; but the slightest current 
will produce decomposition; and the color of the mark depends 
upon the strength of the current. 
appeared upon the paper, which gradually grew darker and 
larger, until a flame of fire followed the pen, and burned through 
disappeared, and was then succeeded by a negative current, 
which bleached instead of colored, the paper; this also gradu- 
y increased, until, as with the positive current, it burned the 
Paper, and then subsided, to be followed by the positive current 
again. This state of things continued during the entire evening, 
mF effectually prevented any business being done over the 
Was followed by a current of the reverse polarity. This inva- 
nably occurved, and may be set down as an established fact, that 
the currents from the Aurora Borealis always change their po- 
ity during every wave. ° , 
*g have seen the auroral current produce magnetism, decompose 
chemicals, and produce heat and fire. 
The effects of the magnetic storm of August 28th, 1859, were 
A ht upon the wires during a considerable portion of Satur- 
y €vening, and during the entire day, Sunday. At 6 P.M. the 
line to New Bedford (60 miles in length, running a little west of 
South) could be worked only at intervals, although, of course, no 
The of the Aurora Borealis were visible to the eye at that hour, 
The same was true of the wires running east through the state 
: it on Sunday, and yet there was a current upon it during the 
. day, which caused the keepers of the electro-magnets to 
_ ®Pen and close as the waves came on and receded. 
