After it a voice roareth: he thundereth with the voice of his excellency; and he will not stay them when his voice is heard. After it a voice roareth - After the flash has been seen, the peal is heard; and this will be more or fewer seconds after the peal, in proportion to the distance of the thunder cloud from the ear. Lightning traverses any space without any perceivable succession of time; nothing seems to be any obstacle to its progress. A multitude of persons taking hands, the first and the last connected with the electric machine, all feel the shock in the same instant; and were there a chain as conductor to go round the globe, the last would feel the shock in the same moment as the first. But as sound depends on the undulations of the air for its propagation, and is known to travel at the rate of only 1142 feet in a second; consequently, if the flash were only 1142 feet from the spectator, it would be seen in one second, or one swing of the pendulum, before the sound could reach the ear, though the clap and the flash take place in the same instant, and if twice this distance, two seconds, and so on. It is of some consequence to know that lightning, at a considerable distance, suppose six or eight seconds of time, is never known to burn, kill or do injury. When the flash and the clap immediately succeed each other, then there is strong ground for apprehension, as the thunder cloud is near. If the thunder cloud be a mile and a half distant, it is, I believe, never known to kill man or beast, or to do any damage to buildings, either by throwing them down or burning them. Now its distance may be easily known by means of a pendulum clock, or watch that has seconds. When the flash is seen, count the seconds till the clap is heard. Then compute: If only one second is counted, then the thunder cloud is within 1142 feet, or about 380 yards; if two seconds, then its distance is 2284 feet, or 761 yards; if three seconds, then 3426 feet, or 1142 yards; if four seconds, then the cloud is distant 4568 feet, or 1522 yards; if five seconds, then the distance is 5710 feet, or 1903 yards; if six seconds, then the distance is 6852 feet, or 2284 yards, one mile and nearly one-third; if seven seconds, then the distance of the cloud is 7994 feet, or 2665 yards, or one mile and a half, and 25 yards. Beyond this distance lightning has not been known to do any damage, the fluid being too much diffused, and partially absorbed, in its passage over electric bodies, i.e., those which are not fully impregnated by the electric matter, and which receive their full charge when they come within the electric attraction of the lightning. For more on the rain produced by thunder storms, see on Job 38:25 (note). This scale may be carried on at pleasure, by adding to the last sum for every second 1142 feet, and reducing to yards and miles as above, allowing 1760 yards to one mile.
He thundereth with the voice of his excellency - גאונו geono, of his majesty: nor is there a sound in nature more descriptive of, or more becoming, the majesty of God, than that of Thunder. We hear the breeze in its rustling, the rain in its pattering, the hail in its rattling, the wind in its hollow howlings, the cataract in its dash, the bull in his bellowing, the lion in his roar; but we hear God, the Almighty, the Omnipresent, in the continuous peal of Thunder! This sound, and this sound only, becomes the majesty of Jehovah.
And he will not stay them - ולא יעקבם velo yeahkebem, and he hath not limited or circumscribed them. His lightnings light the world; literally, the whole world. The electric fluid is diffused through all nature, and everywhere art can exhibit it to view. To his thunder and lightning, therefore, he has assigned no limits. And when his voice soundeth, when the lightning goes forth, who shall assign its limits, and who can stop its progress? It is, like God, Irresistible.