; AMERICAN 
JOURNAL OF SCIENCE AND ARTS. 
[SECOND SERIES.] _ 
Arr, XXVIL—The Aurora, viewed as an Electric Discharge be- 
tween the Magnetic Poles of the Earth, modified by the Earth's 
Magnetism ; by BeNsamin V. MarsH. With two plates. 
_ Ir was shown by Dalton that the appearances presented by 
_ the Aurora could be explained by supposing the existence of 
| horizontal bands of luminous matter near. y at right angles to the 
_ Magnetic meridian, and of columns parallel to the dipping needle, 
Be ~—the former constituting the auroral “arch,”and the latter the 
__ Streamers”—and he suspected that the streamers either stood 
upon the arch, or depended from it. 
| Subsequent observations have confirmed the reality of these 
bands and columns, and have shown that, ordinarily, the stream- 
ers stand upon the arch as a base. When the arch is nearly over- 
head we see the streamers through it, as through a curtain, and 
‘© auroral arch as seen over the northern horizon is gener- 
¥ 4 pérfect and regular are of a circle, its highest point being 
