_Martin Folkes_, Esq; LL. D.
President of the Royal Society.
Since I had the honour to lay before the Society, in the spring, my
thoughts upon earthquakes: we have had many further opportunities of
reflecting upon that most awful, and hitherto unusual appearance. An
earthquake was felt at _Eastwell_ in _Kent_, on _monday march_ 12, and on
_sunday, march_ 18, at _Portsmouth_, the _Isle of Wight_, _Southampton_,
and along the coast of _Sussex_, the isles of _Guernsey_, _Jersey_.
_April_ 2, a smart earthquake at _Manchester_, _Liverpool_, _Taunton_,
_Bath_, _Flint_, _Lancaster_, _Wrexham_, reaching 40 miles north and
south: 70 miles east and west. Since then at _Rome_, _Naples_, _Leghorn_;
in the south of _France_, and at _Pau_ under the _Pyrenean_ mountains:
_Oporto_, at _S. Macaire_ in _Guienne_, _Messina_ in _Sicily_, _Munich_ in
_Bavaria_, &c. &c. so that the year 1750, may rather be called the year
of earthquakes, than of jubilee. For since _February_ last, when they
began with us at _London_; as far as I can learn, they have appear'd in
many parts of _Europe_, _Asia_, _Africa_, and _America_. And have likewise
revisited many counties in our own island, and at length, on the 30th of
last _september_ gave much the most extensive shock, we have seen here in
our days.
It may be well expected, that these frequent visits, in themselves so very
extraordinary, to us so rare, and _that_ in one year, should keep up our
attention: and as to my own part, induce one to reflect, on what I before
offer'd concerning them; and be a sufficient apology for the present paper.
We have been acquainted, by those who remember it, that in the earthquake
of nov. 1703, which happen'd in _Lincolnshire_, the weather was calm,
close, gloomy, warm, and dry; in a degree highly unusual, at that season.
And thus it has been with us, all the year. And from the numerous accounts
we have receiv'd at the Royal Society, in the beginning, and ending of the
year; where any mention is made of the weather; they all agree in the like
particular. Which is consentaneous to what I remark'd, as the constant
forerunner of earthquakes; and what prepares the earth's surface, for the
electrical stroke: which I asserted to be the cause of them.
In _may_ last, we had a paper read at the Royal Society, concerning
the second earthquake felt by us at _London_, on the 8th of _march_. A
shepherd belonging to Mr. Secretary _Fox_ at _Kensington_ (the sky being
perfectly serene, and clear) was much surprised with a very extraordinary
noise in the air, rolling over his head, as of cannon close by. He
likewise thought, that it came from the north-west, and went to the
south-east: a motion quite contrary, to what must have been the case, if
it were really of cannon. This noise pass'd rushing by him; and instantly
he saw the ground (a dry, and solid spot) wave under him, like the face
of the river. The tall trees of the avenue, where he was, nodded their
tops very sensibly, and quiver'd like a shaken spear. The flock of sheep
immediately took fright, and ran all away together, as if dogs had pursued
them. A great rookery in the place, were equally alarm'd, and after an
universal clangor, flew away; no less than if chaced by hawks.
I was likewise inform'd, that in the same earthquake, a great parcel of
hens, and chickens, kept at that time in _Gray's-inn-lane_, upon the
shock, ran to the roost, affrighted. And the like was observ'd of pigeons.
And in our last account of the earthquake from _Northampton_, 'tis
remarked, that the birds in cages put their heads under their wings, as
to hide themselves.
_June_ 21, at the Royal Society, Mr. _Jackson_ potter at _Lambeth_, gave
an account of some boats, cobles and lighters in the river, at that time;
the people in them seem'd to feel, as if a porpoise, or some great fish
had heav'd and thump'd at the bottom of the vessels. This is sometimes the
case of ships at sea, when all is perfectly calm: which seems evidently
owing to an electrical impression on the water.
In the evening-post of _june_ 23, we had a paragraph from _Venice_, that
a terrible earthquake had been felt lately in the little rocky isle of
_Cerigo_, in the _Mediterranean_, south of _Morea_. It threw down a great
number of houses; and above 2000 of the inhabitants were buried in the
ruins.
Another earthquake about that time, happen'd in _Switzerland_; which split
a vast, rocky mountain; and an old castle wall of an immense thickness.
All these circumstances, and many more confirmed me in my former opinion.
But since then, these wonderful movements have stalk'd round the globe:
and again been lately felt in our own island; happily for us, to the
terror only, of many thousand people: beside those concussions of this
sort that appear'd in the western parts, in the more early time of the
year.
I receiv'd a letter from my friend _Maurice Johnson_, Esq; the founder,
and secretary of the Literary Society of _Spalding_; which has now
subsisted these 40 years. He acquaints me, that on _thursday_, 23d of
_August_ last, an earthquake was very sensibly felt there, about seven
o'clock in the morning; throughout the whole town and neighbourhood;
and many miles round: but that it chiefly spread itself northward, and
southward. He says, that for a fortnight before, the weather had been
serene, mild, and calm. And one evening, there was a deep red _aurora
australis_, covering the cope of heaven, very terrible to behold.
This same shock was felt at _Grantham_, _Stamford_, and _Milton_ by
_Peterborough_; and generally at all the intermediate places: and from
_Spalding_ it fled northward, along the sea shore, to _Boston_: thence up
_Boston_ river, to _Lincoln_.
Since then, I had a letter from Mr. Alderman _Taylor_ of _Stamford_,
giving an account of another earthquake, that happen'd there, _september_
30, at 36 minutes after twelve o'clock at noon. He describes it thus.
They were suddenly surprised with an uncommon noise in the air, like the
rolling of large carriages in the streets, for about 20 seconds. At the
same instant they felt a great shake, or snap, as he calls it; insomuch
that it sensibly shook a punch-bowl, which was in his parlour, and made
it ring. He says, it was perceiv'd of most of the people of _Stamford_,
who generally ran out of their houses. At _Oakham_ the chief town of
_Rutland_, the congregation ran out of the church whilst the preacher was
in the pulpit. All the towns round _Stamford_, were sensible of it: and at
_Peterborough_, down to _Wisbech_.
Thus far the Alderman. But we have had many advices from all hands, at
the first, and second meetings of the Royal Society, for the winter
season; with further particulars relating to this great concussion. That
it was felt at the same time, at _Rugby_ in _Warwickshire_, and reach'd
to _Warwick_, at _Lutterworth_, in _Leicestershire_: at _Leicester_, and
round about. It extended itself to _Coventry_, _Derby_, _Nottingham_,
_Newark_; then came eastward to _Harborough_, _Towcester_, _Northampton_,
_Rowel_, _Kettering_, _Wellingborough_, _Oundle_, in _Northamptonshire_;
_Uppingham_, _Oakham_ in _Rutland_; _Stamford_, _Bourn_, _Grantham_,
_Spalding_, _Boston_, and to _Lincoln_ in _Lincolnshire_; _Holbech_, and
all _Holland_ in that county. _Peterborough_, _Wisbech_, in the isle of
_Ely_; together with all the intermediate, and adjacent places. Then it
passed over the whole breadth of _Ely_ fen: was felt at _Mildenhall_, and
reach'd to _Calford_ by _Bury_ in _Suffolk_, and the country thereabouts;
of which we had notice from lady _Cornwallis_. An extent from _Warwick_
to _Bury_ of about 100 miles in length; and generally speaking, 40 miles
in breadth. And this vast space was pervaded by this amazing motion, as
far as we can get any satisfaction, in the same instant of time. They
describe it, that the houses totter'd, and seem'd to heave up, and down:
tho' it lasted but a few seconds. It was attended with a rushing noise,
as if the houses were falling, and people were universally so affrighted,
as to run out; imagining that their own, or their neighbours houses
were tumbling on their heads. In the villages around, the people being
generally at divine service, were much alarm'd: both with the noise,
which exceeded all the thunder they had ever heard, beyond compare: and
with the great shock accompanying; which was like somewhat, as they
imagin'd, that rush'd against the church-walls, and roof. Some thinking
the pillars crack'd, many that the beams of the roof were disjointed;
and all, that the whole was falling. And happy were they that could get
out first. Many people fancied, that nests of drawers, and cabinets, or
the like heavy things, were fallen down above stairs: or that chimnies
had broke thro' the roof of the house: or that some persons fell down
stairs: and the like. Some perceived the crackling of inward wainscots or
partitions: as Dr. _Mortimer_ and I, observ'd in our first and second
shocks at _London_. A few slates, tiles, and parts of chimneys fell from
some houses: pewter, china, glasses and brass from shelves. A clock bell,
chamber bell sometime struck: windows universally rattled, and the like
circumstances of tremor.
In regard to circumstances, they were pretty similar throughout. Many
people sitting in their chairs relate, that they and their chairs were
several times sensibly lifted up and set down again. A stack of chimneys
were thrown down in _College-lane_; a place retaining the memory of a
sort of university once beginning at _Northampton_. The windows of houses
rattled throughout the whole town: but no mischief done: in general it was
frightful, and innocuous.
They fancied there, the motion of it, as they expressed it, to be
eastward. In streets that run north and south, the houses on the east
side of the way, were most affected. And Dr. _Stonehouse_'s dwelling,
the strongest in the town, was most sensibly shaken. So it was likewise
observ'd, that churches were most subject to its violence. They thought
too, that the motion seem'd rather horizontal, or lateral, than upward.
Some counted the pulses distinctly, to the number of four: that the
second, and third pulses were stronger, than the first, and fourth.
From all these various accounts, there was no sulphureous smell, or
eruption; no fissures in the ground perceived. Yet several people were
sick upon it: infinite numbers terribly affrighted, and as soon forgot
the impression of it; or talk'd of it in a merry strain; as commonly with
us at _London_. So little are the vulgar assessed, without something very
sensible; and so soon is the sense of it worn out!
It was more evidently perceiv'd, by people standing; most, by those
that were sitting: least, by such as were walking: and in upper stories
of houses, more than in lower; or in cellars. Some coming down stairs,
were in danger of being thrown forwards. Several sitting in a chair, and
hearing the hollow, thundering noise, and thinking it was a coach passing
by; when they attempted to get up, to see what it was, they were thrown
back again in their chair. Some heard the wainscot crackle, Some sitting
in their chairs leaning forwards, were thrown down on their hands, and
knees. Some people heard the noise without feeling the shock: others felt
the shock without hearing the noise. Some in a standing posture, were
forc'd to lay hold on a table, to keep themselves from falling.
It was particularly remarked (as before observ'd) that birds in cages
were sensibly affrighted; thrusting their heads under their wings. Mrs.
_Allicock_ of _Loddington_, _Northamptonshire_, a lady in child-bed, was
so affected, that it caused her death. Mrs. _Hardy_, another lady in the
same circumstance, and in the same county, likewise expired upon it, Some
people felt a sudden shortness of breath, that they were forc'd to go out
into the open air, it so affected the pulmonary nerves. Many were taken
with head-achs, and other sicknesses.
These are, in general, the circumstances and observations made, at
the time of these earthquakes; when we recollect ourselves, after the
suddeness, and fright. Give me leave to make the following remarks
therefrom.
1st. As far as we can possibly learn, where no one can be prepar'd,
at different places, by time keepers; this mighty concussion was felt
precisely at the same instant of time; being about half an hour after
twelve at noon. This, I presume, cannot be accounted for, by any natural
power, but by that of an electrical vibration; which, we know, acts
instantaneously.
2dly, Let us reflect on the vast extent of this trembling, 100 miles in
length, 40 in breadth, which amounts to 4000 square miles in surface. That
this should be put into such an agitation, in one moment of time, is such
a prodigy; as we should never believe, or conceive, did we not know it
to be fact, from our own senses. But if we look for a solution of it, we
cannot think, any natural power is equal to it, but that of electricity;
which acknowledges no sensible transition of time; no bounds.
3ly, We observe, the vulgar solution of subterraneous eruptions receives
no countenance, from all that was seen, or felt, during these earthquakes.
It would be very hard to imagine, how any such thing could so suddenly,
and instantaneously operate, thro' this vast space: and _that_ in so
similar, and tender a manner over the whole, thro' so great a variety, as
well as extent of country; as to do no mischief. A philosophical inquirer
in _Northamptonshire_ had his eye particularly on this point, takes
notice, there were not any fissures in the ground; any sulphureous smells,
or eruptions any where perceiv'd; so as to favour internal convulsions of
the earth. The reverend Mr. _Nixon_ of _Higham_, and Mr. _Smith_, in his
letter from _Peterborough_ take notice, that they could not learn, there
were any sort of eruptions out of the earth, any where: no smoke, vapor,
or smell: tho' they made sufficient inquiry about that circumstance,
according to particular direction. Yet we learn from a letter at
_Uppingham_ in _Rutland_, that a plaister floor became crack'd thereby.
These kind of floors are frequent in this country; what we call _stucco_
in _London_: and it gives us a good notion of the undulatory vibration,
produc'd by an earthquake; which some have compar'd to that of a musical
string: others to that of a dog, or a horse shaking themselves, when they
come out of the water. This last comparison would have pleased some of the
ancients, who would needs fancy, that the globe of the earth was a great
animal. _Plato_, _Plutarch_, and others, had such kind of sentiments.
Whence one may imagine, that they would conceive an earthquake to be, as
when a horse shakes a part of his skin, upon a fly touching him. Some of
our correspondents express the motion of an earthquake to be like a boat
lifted up by one wave, let down by another.
4ly, The former earthquake that happen'd at _Grantham_, _Spalding_,
_Stamford_, (which towns lie in a triangle) took up a space which may, in
gross, be accounted a circle of 30 miles diameter: the center of which is
that great morass, called _Deeping-fen_. This comprehends 15 miles of that
30, in diameter: and where probably, the electrical impression was first
made. Much the major part of _Deeping-fen_ is under water in the winter
time; underneath 'tis a perfect bog. Now it is very obvious, how little
favorable such ground is, for subterraneous fires.
In the second earthquake, not only this country was affected again,
but likewise a much larger space of the same sort of fenny ground,
rather worse than the former: all _Donnington-fen_, _Deeping-fen_,
_Croyland-fen_, _Thorney-fen_, _Whitlesea-fen_, _Bedford_ level, and the
whole extent of _Ely-fen_, under various denominations. This country,
under the turf, abounds with subterraneous timber of all sorts; fir, oak,
and brush-wood: and stags horns. Now and then they find a quantity of
hazel nuts, crouded together on an heap. I have some of them. This is a
matter common to all boggy ground over the whole globe, Such things are
the ruins of the _antediluvian_ world, washed down from the high country
where they grew, were here lodg'd upon the subsiding of the waters, and
by time are o'ergrown with the present turf. They that seek for any other
solution of this affair, than the universal _Noachian_ deluge, want to
account for a general effect, by a partial cause: and shut their eyes,
both to the plain history of this matter; and to the infinite, notorious
demonstrations of it, from fossil appearances.
5ly, All this country, tho' underneath 'tis a watry bog, yet thro' this
whole summer, and autumnal season (as they can have no natural springs
in such a level) the drought has been so great on the superficies, that
the inhabitants were oblig'd every day, to drive their cattle several
miles, for watering. The drought was greater, than has been known in the
memory of any one living. This shows how fit the dry surface was, for an
electrical vibration. And we learn from hence, this important particular,
that it reaches but very little below the earth's surface.
Mr. _Johnson_, in another letter which he wrote to me concerning the
second earthquake observ'd at _Spalding_; says upon this occasion, he was
obliged to scour his canal, and deepen it: that they came to a white,
quicksand; which afforded to all the neighbourhood, excellent water in
plenty.
In the gravelly soil of _London_; and where the two shocks were felt by
us, in the beginning of the year; we know, there is not a house in the
whole extent of this vast city, and all around it, but a spring of water
is ready, upon digging a well, Whence we have much reason to believe, that
the interior of the earth, is like a sponge soak'd in water. So that the
only dry part is the superficies, which is the object, and the subject
of that electric vibration; wherein, according to my sentiments, an
earthquake consists.
This shews the mistake of the ancients, who fancying that earthquakes
proceeded from subterraneous eruptions, built their prodigious temple of
_Diana_ at _Ephesus_, upon a boggy ground, to prevent such a disaster,
The marshy part of _Lincolnshire_, being my native country, the adjacent
fen, together with that in the isle of _Ely_, I have been perfectly
acquainted with; from one end to the other, ever since I knew any thing.
This vast extent of fenny level, from near _Cambridge_ in the south,
to near _Horncastle_ in the north, is 70 miles in length. And when I
perceiv'd, that it was, in whole, or in part, shaken by both the last
earthquakes: I could not but see, that it was no less than a demonstration
against the old notion of their cause.
6ly, Earthquakes are truly most violent, in a rocky country: because the
shock is proportionate to the solidity of the matter electrify'd. So
that rocks, cliffs, quarries, old castle walls, and strong buildings,
are most obnoxious to the concussion. The isle of _Cerigo_ was more
liable, and more rudely handled by the late earthquake; both because
it was an isle, and because it was rocky. So we must say of the late
earthquake in _Switzerland_, that split the mountain, and the old castle
wall. Whence Mr. _Johnson_ in his second letter, says, it cracked a very
strong brick-house in _Gosberton_ by _Spalding_. Dr. _Doderidge_ observes
from _Northampton_ that Dr. _Stonehouse_'s dwelling being a very strong
one, was most sensibly shaken. And throughout the whole compass of this
great earthquake, we find, both the noise, the shock, and the terror
was greatest at the churches, whose walls and bulk made more resistance
than houses. And generally speaking, the churches throughout this whole
extent have very fair, and large towers, and very many remarkable spires
all of good stone, which no doubt quiver'd very much at top, if we could
have discern'd it. This same vibration impressed on the water, meeting
with the solid of the bottom of ships, and lighters, gives that thump
felt thereon; just as in common electrifying, we feel the stroke upon the
joints of our limbs chiefly. Yet of the millions of ordinary houses, over
which it passed, not one fell. A consideration which sufficiently points
out to us, what sort of a motion this was not, what sort of a motion it
was, and whence deriv'd; not a convulsion of the bowels of the earth,
but an uniform vibration or undulation of its surface, aptly thought
like that of a musical string: or what we put a drinking glass into, by
rubbing one's finger over the edge; which yet brought to a certain pitch,
breaks the glass; undoubtedly an electric repulsion of parts. And from
this remarkable similarity in the appearance of earthquakes we gather an
invincible argument against the old opinion of their cause; for the tumult
of subterraneous eruptions can have no possible place herein.
7ly, We find from all accounts, ancient and modern, that the weather
preceding these shocks, was mild, warm, dry, serene, clear, frosty: what
notoriously favours all our electrical experiments. This is particularly
observ'd by Mr. _Johnson_ and Mr. _Smith_, and other accounts. In the
extensive shock of _sunday march_ 18, along the _Sussex_ coast, they take
notice from _Portsmouth_, that the day was serene, warm, and dry, and
that a shower of rain fell immediately before the shock. Mr. _Bowman_ of
_Moulsey_ observ'd a shock there on _may_ 24 last, and says, the air was
perfectly serene, and clear. We very well know, that generally, all last
winter spring, summer, and autumn, have been most remarkably of this kind
of weather; more so, than has been observ'd in our memory; and have had
all those requisites, appearances, and preparations, that notoriously
cause electricity, that promote it, or that are the effects of it.
8ly, We find the blood-red _australis aurora_ preceding at _Spalding_,
as with us at _London_. At the time of the earthquake at _Manchester_
this year, it accompanied it. And this year has been more remarkable than
any for fire-balls, storms, wind, thunder, lightnings, and coruscations,
almost throughout all _England_. A large ball of fire, with a long
fiery tail on _july_ 22, that passed over great part of _England_
northward. Another seen over _London_, passing from west to east, in
_october_. Coruscations were seen just before that extensive shock of
70 miles long felt from _Lancaster_ to _Wrexham_, on _april_ 2, last.
Fire-balls more than one were seen in _Rutland_, and _Lincolnshire_: and
particularly observ'd. And Mr. _Smith_ from _Peterborough_ writes, that
a fire-ball was seen the morning of the earthquake, in the upper part
of _Northamptonshire_. All these kind of meteors are rightly judg'd to
proceed from a state of electricity in the earth and atmosphere: and how
far they are actually concerned in causing earthquakes, time, and accurate
observation must inform us.
9ly, Mr. _Johnson_ in both his letters to me, on the first and second
earthquakes, at _Spalding_, remarks particularly, of their effects being
mostly spread to the north and south, and especially felt on the sea
coast. We may observe, that such is the direction of _Spalding_ river,
which both conducts, and strengthens the electric vibration: conveying it
along the sea-shore thence, up to _Boston_ channel; and so up _Boston_
river to _Lincoln_, as we discern, by casting our eye on a map.
We observe further, that the main of this second earthquake display'd
its effects along, and between the two rivers, _Welland_ and _Avon_:
and _that_ from their very origins, down to their fall into the sea. It
likewise reach'd the river _Witham_, which directed the electric stream
that way too, to _Lincoln_. For which reason, as there meeting the same
coming from _Boston_, the shock was most sensibly felt. It reach'd
likewise to the _Trent_ at _Nottingham_, which convey'd it to _Newark_.
The first electrical stroke seems to have been made on the high ground
above _Daventry_, in _Northamptonshire_; where the _Roman_ camps
are, made by _P. Ostorius_ the proprætor. From thence it descended
chiefly eastward, and along the river _Welland_, from _Harborough_ to
_Stamford_, _Spalding_, the sea: and along the river _Avon_, or _Nen_, to
_Northampton_, _Peterborough_, _Wisbech_ to the sea. It spread itself all
over the vast level of the isle of _Ely_; further'd by very many canals,
and rivers, natural, and artificial, made for drainage. It was still
conducted eastward up _Mildenhall_ river, in _Suffolk_, to _Bury_, and the
parts adjacent. All this affair duly consider'd, is a confirmation of the
doctrine I advanc'd on this subject.
10ly, I apprehend, it was not the noise in the air, as of many cannon let
off at once, preceding the earthquake, that so much affrighted people, or
affected the sheep, the rookery at _Kensington_, the hen and chickens in
_Gray's-inn-lane_, the pigeons. It could not be barely the superficial
movement of the earth, that disturb'd them all at once. I judge it to be
the _effect_ of electricity, somewhat like what causes sea sickness; such
a sort of motion, as we are not accustomed to. So the earthquake affects
all those of weak nerves, or that have nervous complaints; obnoxious to
hysterics, colics, rheumatick pains in their joints; several women were
seized with violent head-achs, before both the shocks we felt in _London_.
It was this that gave the people a shortness of breath. Mr. _Smith_ from
_Peterborough_ speaks of a person that found himself very sick upon it.
This made the dog run whining about the room, seeking to get out: this
made the fishes leap up in the pond at _Southwark_; like as the experiment
of electrifying the fishes: it makes them sick. And this causes the birds
in cages to hide their heads under their wings, because they cannot fly
away. Which is commonly observ'd of them in _Italy_, and countries, where
earthquakes are more frequent.
11ly, I observe, the shepherd at _Kensington_ thought the motion of the
earthquake, and the sound, was from the north-west to south-east; the like
Mr. _W. Smith_ from _Peterborough_. On the contrary, Mr. _Byfield_ the
scarlet dyer in _Southwark_, thought the noise came from the river below
bridge, and went toward _Westminster_; where it rattled so, that he did
not doubt, but that the abbey-church was beaten down.
Dr. _Parsons_ took pains to find out the way of the motion of the
earthquake, from the different position of people's beds; but from the
contradictory answers given, he cou'd not obtain any satisfaction, as
to that point. All this, and what was observ'd from _Northampton_, of
the motion being thought by some, to be upward and downward; by others
rather horizontal, or lateral: the counting the pulses, and the like, only
points out to us the prodigious celerity, and the vibratory species of the
motion of an earthquake. But far, very far is this from being owing to the
tumultuous ebullition, the irregular hurry of subterraneous explosions.
12ly, How the atmosphere, and earth, are put into that electric and
vibratory state, which prepares them to give, or receive the snap, and the
shock, which we call an earthquake; what it is, that immediately produces
it, we cannot say: any more than we can define, what is the cause of
magnetism, or of gravitation; or how muscular motion is perform'd, or a
thousand other secrets in nature.
We seem to know, that the author of the world has disseminated ethereal
fire, thro' all matter, by which these great operations are brought about.
This is the subtil fluid of Sir _Isaac Newton_, pervading all things:
the occult fire diffused thro' the universe, according to _Marsilius
Ficinus_ the platonic philosopher, on the _Timeus_ of his master. All
the Platonists insist on an occult fire passing thro', and agitating all
substance, by its vigorous and expansive motion.
Before them, _Hippocrates_ writes in the same sense, _I. de victûs
ratione_, that this fire moves all in all. This ethereal fire is one of
the four elements of the ancients. It lies latent, and dispersed thro'
all the other three, and quiescent: till collected into a quantity, that
over-balances the circumjacent; like the air crouded into a tempest: or
till it is excited, by any proper motion.
This fire gives elasticity: and elasticity or vibration is the mother of
electricity. We don't so much wonder at phosphorus arising from animal
substances; for this fire is in water, and betrays itself to our senses,
in salt water. Many a time when I have passed the _Lincolnshire_ washes,
in the night time; the horse has seem'd to tread in liquid flames. The
same appearance is oft at the keel of a ship. Fire exists in water, says
_Pliny_, as well as in human bodies. _nat. hist._ II. 107. Loaf sugar
beaten in the dark is luminous. Many vegetables, as indian cane, and
rotten wood the like, as _Bartholin_ largely recites, _de luce hominum_
c. 4. All electric bodies have this privilege: that is, they more easily
discover it. Amber, gum lac, naptha, bitumens, some precious stones.
My old friend Mr. _Stephen Gray_ the father and great propagator of
electricity, show'd me experiments therein, in the year 1705, then at
_Corpus Christi_ college in _Cambridge_. Afterward in the year 1719, he
show'd by experiments before the Royal Society, that paper, ribbands,
silk, sattin, cloth, shavings, linen, goldbeaters skin, and in short,
almost all kind of substances discover electrical sparks of fire in the
dark: especially when well warm'd before the fire, or in a cold, dry,
nitrous air, and in a room where there is no company. This same quality is
found _in vacuo_, as Dr. _Desaguliers_ show'd before the Royal Society,
_march_ 31, 1720. He took an exhausted glass globe, and caused it to be
turn'd round violently, in an engine: by rubbing the hand upon it, it was
illuminated within side, with purple streams. This gave foreigners the
idea of using a glass globe, in electrical experiments.
The operation of the ethereal fire is various, nay, infinite, according
to its quantity, and degree of incitement, progress, hindrance, or
furtherance. One degree keeps water fluid, says the learned bishop of
_Cloyne_: another turns it into elastic air, and air itself seems nothing
else, but vapors, and exhalations render'd elastic, by this fire.
This fame fire permeates, and dwells in all bodies; even diamond,
flint, and steel. Its particles attract with the greatest force, when
approximated. Again, when united, they fly asunder, with the greatest
force, and celerity; it resists nothing quiescent, but when put into
motion, it disdains all resistance. All this is according to the laws
prescrib'd by the sovereign architect. This is the life, and soul of
action, and reaction, in the universe. Thus has the great author provided
against the native sluggishness of matter! light, or fire in animals, is
what we call the animal spirits; and is the author of life, and motion.
But we know not the immediate mode of muscular motion; any more than how,
in inanimate matter, it causes the vibrations of an earthquake.
Of this fire, the excellent _Manilius_ thus writes, who liv'd in the time
of _Augustus_.
_Astronom._ I.
_Sunt autem cunctis permisti partibus ignes;
Qui gravidas habitant fabricantes fulmina nubes:
Et penetrant terras, Ætnamq; imitantur Olympo:
Et calidas reddunt ipsis in fontibus undas.
Ac silice in duro, viridiq; in cortice sedem
Inveniunt; cum silva sibi collisa crematur.
Ignibus usq; adeo natura est omnis abundans!_
Which may thus be english'd.
Fire universal nature traverses.
It makes the thunderbolt in tumid clouds:
In dire Vulcano's penetrates the earth:
And sends the boiling water from its springs.
In hardest flint, and softest wood it dwells:
Which by collision shows itself in flame.
With fire so pregnant is all nature found!
13ly, The great question then with us, is how the surface of the earth
is put into that vibratory and electric state, by heat and driness? we
must needs acquit the internal of the earth from the charge of these
superficial concussions. How then is the ethereal fire crouded together,
or excited, so as to cause them; seeing in our ordinary electrical
experiments, we make use of friction?
But that friction alone does not excite electricity, we know from the
obvious experiment of flint and steel, where the suddenness of the stroke,
and hardness of the matter does it. Another method of exciting it, is
the letting off a number of great guns, which so crouds the ethereal
fire together, as to electrify glass windows; observ'd by my friend the
reverend Dr. _Stephen Hales_. The _aurora borealis_, _australis_, all kind
of coruscations, meteors, lightning, thunder, fire-balls are the effects,
and may reciprocally be the cause of electricity; but how in particular
we know not. Come we to the animal world, we must needs assert, that all
motion voluntary, involuntary, generation, even life itself: all the
operations of the vegetable kingdom, and an infinity more of nature's
works, are owing to the activity of this electric fire, the very soul of
the material world. And in my opinion, 'tis this alone, that solves the
famous question, so much agitated with the writers in medicine, about the
heat of the blood. How these, how earthquakes are begun, propagated, we
are yet to seek.
We may readily enough presume, that the contact between the electric, and
the non-electric, which gives the snap, and the shock, must come from
without, from the atmosphere. Perhaps by some meteor that crouds the
ethereal fire together: which then flies off with that immense force that
causes the earthquake. In the point of contact on the earth's surface,
the same thing is done, perhaps, another time, by a shower of rain. Our
thoughts upon this matter must needs be as immature, as they are novel.
But we may readily conclude, that tho' the original stroke comes from the
atmosphere, yet the atmosphere has no further concern in it: no aereal
power, or change therein, can propagate itself so instantaneously, over
so vast a surface, as 4000 miles square. Therefore the impetuous rushing
noise in the air, accompanying the shock, is the effect, and not the
cause. And all this is strongly confirm'd by this observation, that the
barometer and thermometer receiv'd no change upon the earthquakes.
But surely, there is not a heart of flesh that is not affected with so
stupendous a concussion! let a man estimate his own power, with that which
causes an earthquake; and he will be persuaded, that somewhat more than
ordinary is intended by so rare and wonderful a motion. That great genius
_Hippocrates_, makes the whole of the animal œconomy to be administred,
by what we call nature. And nature alone, says he, suffices for all
things, to animals: she _knows_ herself, and what is necessary for them.
We must extend this thought to the inanimate world. And can we deny then,
that he here means a conscious and intelligent nature, that presides
over, and directs all things, moves the ethereal spirit or fire, that
moves all things: a divine necessity, but a voluntary agent, who gives
the commanding nod, to what we commonly call nature, the chief instrument
in the most important operations of the vast machine, as well as in the
ordinary ones, particularly the human one: administring the whole œconomy
(as he says) without noise, unseen, unfelt. And this leads us,
14ly, Lastly, in regard to the spiritual use we ought to make of these
extraordinary _phænomena_, or of our inquiries about them, I shall first
observe, that we find abroad, several of these earthquakes this year have
been very fatal. In the last we read of, at _Philippopoli_ in _Thrace_,
the whole city was destroyed, above 4000 inhabitants killed. At home,
where above half a score separate concussions have been felt, there has
not been one house thrown down, one life lost. This ought to inspire us
with a very serious reflection about them; nor is it altogether unworthy
of our remark, that they began with us in _London_, in _february_ last:
and after visiting the circle of the globe, at present, end with us.
2dly, We may observe, that if we did but read the works of _Hippocrates_,
_Plato_ and his followers; of _Tully_, _Galen_, and the like ethic writers
of antiquity; whilst we study, and try the affections of matter; we should
improve in philosophy, properly speaking: we should lift up our minds from
these earthly wonders, and discern the celestial admonitions, they present
to us.
The original meaning of the word philosophy, was rightly apply'd to
moral wisdom. We who have advanc'd both the natural, and moral, should,
as the ancients did, join them both together. By this means, we gather,
the truth of the highest, and most excellent philosophy, to be found in
those volumes of first antiquity, which we call sacred: and which, 'tis
our peculiar, and inestimable happiness to possess. We should adore that
divine light, which they hold forth to us. Especially in a country, where
the principles of true religion are open, and undisguised: where the
establish'd profession of it is rational, noble and lovely: worthy of the
moral governor of the world; fit for him to enjoin: for us to practise,
with pleasure and effect.
_november_ 7, 1750.
W. Stukeley.
Read at the Royal Society, _december_ 6.
_FINIS._
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