the turrets above, and at the crags below. It was so close that we quailed at its darts. It seemed to scorch us,—we were in the very focus of the storm. The thunder was simultaneous with the flashes; short and sharp, and more like the noise of a door that is violently slammed, multiplied a thousand-fold, than any noise to which I can compare it.
When I say that the thunder was simultaneous with the lightning, I speak as an inexact person. My meaning is that the time which elapsed between seeing the flash and hearing the report was inappreciable to me. I wish to speak with all possible precision, and there are two points in regard to this storm upon which I can speak with some accuracy. The first is in regard to the distance of the lightning from our party. We might have been 1100 feet from it if a second of time had elapsed between seeing the flashes and hearing the reports; and a second of time is not appreciated by inexact persons. It was certain that we were sometimes less than that distance from the lightning, because I saw it pass in front of well-known points on the ridge, both above and below us, which were less (sometimes considerably less) than a thousand feet distant.
Secondly, in regard to the difficulty of distinguishing sounds which are merely echoes from true thunder, or the noise which occurs simultaneously with lightning. Arago entered into this subject at some length in his Meteorological Essays, and seemed to doubt if it would ever be possible to determine whether echoes are always the cause of the rolling sounds commonly called thunder.[1] I shall not attempt to show whether the rolling sounds should ever, or never, be regarded as true thunder, but only that during this storm upon the Matterhorn it was possible to distinguish the sound of the thunder itself from the sounds (rolling and otherwise) which were merely the echoes of the first, original sound.
- ↑ "There is, therefore, little hope of thus arriving at anything decisive as to the exact part which echoes take in the production of the rolling sound of thunder." P. 165, English ed., translated by Col. Sabine: Longmans, 1855.