“To the editors of the Augusta Herald”

Date

4-9-1812

Newspaper

Augusta Herald

Page and Column

Page 2, Column 2 and 4

Newspaper Location

Augusta, Georgia

Serial Number

768

Abstract

More on the electric fluid theory of earthquake origins. Earthquake theory article

Transcript

To the Editors of the Augusta Herald. (Concluded from our last.) YOU ask next, "on what principle the electric fluid, seeks an outlet at the poles of the earth-and why does it not escape from other parts with equal facility, &c." I answer that it is impossible there can be an efflux and absorption at the same time, and place. The electric fluid, is superinduced to enter the earth near the equatorial regions by the excessive quantity discharged on it by the solar rays.-If the extreme cold at the poles of the earth can change water, which is a conductor, into an electric (at 20 below zero ice will emit sparks) the converse must, also, be true-and the excessive heat near the equator must change, (or approximate) the earth, which is an electric, into a conductor. A conducing quality, therefore, is communicated to the earth at the equatorial regions-and its capacity for the retention of electricity encreased, in the same proportion, by cold in the (unreadable). But the air, also is an electric, and in (unreadable) is still colder than the earth itself--(unreadable) an efflux to it from the earth continually takes place, except, as we have stated, when the earth and seas at the poles becomes electric, to that degree, as to prevent the transmittal of it into the atmosphere. Thus then, in common cases, is the electric fluid conducted to the poles of the earth, and transmitted from it into the air, (often in the form of the Aurora Borealis) by the known laws of electricity. Stationary it cannot be, whilst the meterological changes of the atmosphere, and surrounding objects, are continually disturbing, the equilibrium, or equal distribution of the electric principle, in every portion of matter and space. An electric discharge from a cloud, will perceptibly affect the natural quantity of electric matter contained in objects to the distance of five miles-and a rod may be so fixed as to give out sparks or to ring bells, by what is called the returning stroke or efflux of the electric fluid from the land though situated many miles from the flash of lightning that occasioned it. That earthquakes have, and may happen at all seasons of the year, I am well convinced. I meant to draw no general inference from my allusion to the meterological state of the atmosphere in this country preceeding the late earthquakes. As this phenomenon is not here, as in some countries, a common occurrence, the exposition I gave, and the inference I drew, related only to our own case, as effects so uncommon, might fairly be supposed to originate in some unusual circumstance, appertaining, locally, to the country, or to the last season. The question I proposed to answer in the solution alluded to was admitting the theory I had advanced, "why did earthquakes a thing so rare, happen at this particular time" The Aurora Borealis you seem to consider, as not satisfactorily accounted for on the principles of electricity-it claims a distinguished place amongst the grand phenomena of nature, and it certainly, appertains to some momentous principle in the system of nature. If you deny it to be an electric emanation, it behoves you to offer some counter hypothesis. It certainly possesses every characteristick of electricity-the light, verying in its tints, as observable in lightning-the same vibrative flashing-the same inconceivable velocity, &c. If then it be the electric fluid, how came the polar regions filled with such quantities of it, so as by its light, to supply the absence of the sun-but by the means our theory requires? That it is in motion is evident to the sight-and as the electric fluid is never visible but when in motion, through a resisting medium, we may therefore, identify it with lightning, from this circumstance which is always visible when passing through the atmosphere. There are two requisitions to every hypothesis:-- First--that the principle, or agent, on which it rests be really known to exist, and in the circumstances of time and place required. Secondly, that it be equal to and capable of producing the effect attributed to it. Let us submit our doctrine of earthquakes to these invariable tests of truth:-- First--then, as to the existence of the electric fluid under the circumstances required, I will answer in a word that it is ubiquitary, or omnipresent throughout the universe. The earth, particularly is full of it. Insulate an electric machine, by cutting off its communication with the ground, in every possible direction by interposing electries (non-conductors) and you cannot charge it. When, by letting it have a communication with the earth, you have charged it. In opposition to our utmost efforts, it will again return to the earth. If we interpose electrics it will pass through the air to it either silently and invisible, or, if its motion be rapid, in flashes with a snapping noise-And will return again if the machine be kept in motion, to the excited cylinder. It affects to circulate wherever there are conductors-and is disposed, by its own natural laws to resist our utmost efforts. When its equilibrium is destroyed, to a great degree, it bursts through interposing electrics, and tears them in pieces-hence earthquakes, when it would pass thro' the ground, to the atmosphere-but with conductors it is the most tractible agent in nature-we an regulate its motions at pleasure, but its natural tendency is to the earth. Secondly--as to the efficiency of electricity to produce the effects I have attributed to it. It is a known fact that though no body is absolutely imperminable to the electric fluid-yet, that it passes through electrics with great difficulty. Doctor Priestly gives several instances of globes being broken by being over excited in electrical experiments. He says, "the fragments have been thrown with great violence in every direction so as to be very dangerous to by-standers-he gives the particulars of six instances. "When Mr. Bernard's globe burst-a noise was first heard as if something rending to pieces, the explosion followed, &c." Mr. Boulenger, says that glass globes have sometimes burst like bumbs, and have wounded many persons, and that their fragments have penetrated several inches into the wall," sulpher cylinders have been broken in the same manner and reduced almost to powder. Glass and even brimstone is more adhesive than the earth generally is found to be. What, then, is our earth but a larger globe-and capable, no doubt, of containing as much more of the electric principle, as what its bulk is larger than the cylinder of an electric machine, and could it be excited to the same degree, we have no reason to suppose but that it might have been rent to pieces in the same manner. I contend, in fact, that this, partially, happens in many earthquakes. The facts adduced, I presume, sufficiently prove the existence of the agent under the requisite circumstances and its efficiency, &c. I offer the following however as corroborative of both these facts. In the 77th vol. of the Philosophical Transactions, an account is given of a singular accident by an explosion of the electric fluid from the earth. The article was furnished by Mr. Brydone, the celebrated author of a tour through Sicily and Malta, &c. The occurrence in question, happened on the 19th of July, 1785, near Coldstream on the Tweed in Scotland. "The morning was fine, with the thermometer at 68 ° but about eleven o'clock the sky became obscured with clouds in the south east! and between 12 and 1, a storm of thunder and lightning came on. This storm was a considerable distance from Mr. Brydone's house, the intervals between the flash and crack, being from 25 to 30 seconds, so that the place of explosion must have been between five and six miles off; but while our author was observing the progress of the storm, he was suddenly surprised with a loud report neither preceeded, nor accompanied by a flash of lightning, which resembled the explosion of a great number of muskets in such quick succession, that the ear could scarcely discriminate the sounds. On this the thunder and lightning instantly ceased, the clouds began to separate, and the sky soon recovered its serenity. In about an hour Mr. Brydone was informed that a man with two horses had been killed with thunder." On going to the spot "he observed about four and a half feet behind each wheel of the cart a circular hole of about 20 inches diameter, the center of which was exactly in the tract of each wheel. The earth was torn up as if by violent blows of a pick-axe, and the small stones and dust were scattered on each side the road" "To determine whether these were made by the explosion which tore up the ground, the earth was pushed back on the same tracts which it had described on the road, and the marks of fusion were found exactly to correspond with the centre of the bodies." "Our author next gives an account of several phenomena which happened the same day and which were evidently connected with the explosion. A shepherd tending his flocks n the neighbourhood, observed a limb drop down; and said, that he felt at the same time, as if fire has passed over his face, though the lightning and clap of thunder were of a considerable distance. He ran up to the creature, immediately, but found it quite dead. "This happened about a quarter of an hour before Lander was killed, and the place was about 300 yards distant." "A woman making hay, near the bank of the river, fell suddenly to the ground, and called out that she had received a violent blow in the foot, and could not imagine from whence it came. Mr. Bell the minister of Coldstream, when walking in his garden, a little before the accident happened, felt several times a tremor in the ground. The conclusion drawn from these facts by Mr. Brydone, is that at the time of the explosion the equilibrium between the earth and the atmosphere seems to have been completely restored, as no more thunder was heard, nor lightning observed; the clouds were dispelled, and the atmosphere resumed the most perfect tranquility! But how this quantity of electric matter could be discharged from one element, in another (from the earth into the air) without any appearance of fire, he was at a loss to determine. From the whole, it would appear that the earth had acquired a great super abundance of electric matter, which was every where endeavouring to fly off into the atmosphere. Perhaps it may be accounted for from the excessive dryness of the ground, and for many months the almost total want of rain, which is probably the agent that nature employs in preserving the equilibrium between the two elements." ENCY. BRIT. Mr. Brydone further states, that on the 11th of August, in less than a month a smart shock of an earthquake did actually take place. J.E. March 12th, 1812.

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