Prof. E. Loomis on the Aurora of 1859. 325 
Now whatever may be the direction of the current on thé 
surface of the earth, it is evident that if this current travels on 
a telegraph wire, it must appear to move in the direction of the 
wire; and a current moving across the earth’s surface in any 
fixed direction might be forced to travel over telegraph lines 
making various angles with this direction; but its efficiency would 
vary according to the inclination of the conducting wire to the 
direction of the current. The following table shows the effect 
of a current assumed to move from N, 45° E., to S. 45° W. 
Column first contains a list of the telegraph lines; column sec- 
ond shows their directions; column third shows the angle which 
the assumed current makes with each telegraphic line; and col- 
umn fourth shows the fraction of the entire current which would 
be efficient upon such a line. 
Tolga ne a | le 
Boston to Cambridge, West. 45° 071 
adelphia to Pittsburgh, N. 82° W. 53 ‘60 
Pringfi Ibany, N.58 W. 77 29 
in to Manchester, N.26 W. 70 ‘B34 
w Bedford to Boston Bt 52 ‘62 
Fall River to Braintre N.12 E, 33 8 
Richmond to Washington, N.15 ©. 80 87 
Boston to Portland, N.24 E. 21 ‘93 
Philadelphia to New York N.49 E. 4 "99 
Springfield to Boston, | _N.79_-E 84 $3 
ee perhaps be sufficient to explain the effects mentioned in 
vo . 95 
thought inadequate to explain the facts mentioned in vol. xxx, 
Pp. 95, it may be necessary for us to admit, that the direction of 
th casional fluctuations. 
the force of the electric current upon each of the telegraph lines 
had been actually measured by a galyanometer, we should prob- 
ably be able to determine whether the direction of the current 
Was invariable, and what was its prevalent direction. At pres- 
ent we can only infer that all the facts reported are consistent 
with the supposition of electric currents moving to and fro on 
the earth’s urface, whose average direction was from about N, 
45° B. to S. 45° W. : 
e observations published in this Journal, vol. xxxii, pp. 
74-96, give us more definite information respecting the strength 
of the currents as well as their direction. Between Ashford an 
Margate there were recorded 36 north currents and 81 south 
