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bodies on the ground are kept whirling about in the air.
In other cases these small dust-storms are seen slowly advancing, and when numerous, usually proceed in the same direction.
Birds—Kites and Vultures—are often seen soaring high up, just above these spouts, apparently following the direction of the column, as if enjoying it.
My idea is that the phenomena connected with dust-storms are identical with those present in waterspouts and white squalls at sea and revolving storms and tornadoes of all kinds; and that they originate from the same cause viz—moving columns of electricity.”
In 1847, at Lahore, being desirous of ascertaining the nature of the dust-storms, I projected into the air an insulated copper wire on a bamboo on the top of my house, and brought the wire into my room, and connected it with a gold-leaf electrometer and a detached wire communicating with the earth. A day or two after, during the passage of a small dust-storm, I had the pleasure of observing the electric fluid passing in vivid sparks from one wire to the other, and of course strongly affecting the electrometer. The thing was now explained, and since this, I have, by the same means, observed at least sixty dust-storms of various sizes all presenting the same phenomena in kind.”
He continues to describe the dust storm as follows:—“Some of them come on with great rapidity, as if at the rate of forty to sixty miles an hour. They occur at all hours, oftentimes near sunset.
The sky is clear and not a breath moving: presently a low bank of clouds is seen in the horizon, which you are surprised you did not observe before; a few seconds have passed, and the cloud has half filled the hemisphere, and there is no time to lose—it is a dust storm—and helter-skelter every one rushes to get into the house to escape being caught in it.
The electric fluid continues to stream down the wire unremittingly during the continuance of the storm, the sparks oftentimes upwards of an inch in length, and
