The encroachments of the fea from time to time, by its fluctuating pervading ebb and flow, hath fearched out, and carried off many of the laxer fubftances between the Strata ; nay it hath even, by its own force and violence, deftroyed large portions of folid rocks and cliffs, which is well known by every perfon acquainted with the fea fhore: these, together with the larger fubmarine gulphs or fwallets, cannot but influence the maritime Strata, and produce fecondary fubfidencies of the earth; to which we may afcribe thofe contrary and irregular underlies of Fiffures with us, who are fo narrowly fituated between the two channels, and whofe Lodes are remarkably distorted thereby in the parish of St. Agnes, and elsewhere on the fea coafts.

One more effective caufe of the dislocation of Lodes, is that of the general deluge; which deluge, in the parish before mentioned, is evidenced not only in the multiform fractures and interruptions of the Lodes, but in the diftinct and folitary mountain, called St. Agnes Beacon, in the proper British dialect, Carne Bury-anacht, or Bury-anack, the Still Spar-stone Grave; where, fuitable to the name, on the natural remote eminencies thereof are raised three Quartz-ftone Tumuli. The natural circumstances of this mountain are worthy the confideration of a philofopher: for though it is a very high mountain, abutting on the Irish fea or St. George's channel, and rifing pyramidally from the fame at leaft five hundred and forty feet above the sea, yet on the top thereof, under those Tumuli, is discovered by the Tinners five feet deep good arable land or earth; under that, for fix feet deep more, is a fine sort of white and yellow clay, of which tobacco pipes have been made; and beneath this clay is a Stratum, or layer of sea sand, and smooth beach pebbles. Two or three hundred fathoms from the fea, and about eighty fathoms above it, under this fand, is to be seen for five feet deep nothing but fuch beach Stones, as are usually washed on the sea shore, and in many of them grains of Tin: under those Stones, the foil or matter of the earth for fix feet deep; and under that appears again the firm rock, through which Tin Lodes have been wrought at fifty, fixty, or feventy fathoms deep.

It would be needlefs and impertinent to enter here upon a difquifition into the univerfality of the deluge, and the natural means the Almighty used to produce fo unparalleled an event: the greatest naturalifts and philofophers have given different

and

and contradictory folutions of it. I beg leave, however, to obferve, that we are fupplied with innumerable evidences of this grand phenomenon; and notwithstanding we have no exuviæ of land or fea animals buried in our Strata, yet this mountain, of which we have just spoken and given the particular circumstances of its fite and contents, is at once a production and an irrefragable proof of Noah's flood.

It is agreed by moft naturalifts, that fome parts of the prefent dry land were, before the flood, part of the ocean's bed; among which, I suppose, the top of this mountain was placed, till the Almighty cause moved upon the furface of the waters, and directed the bottom of the fea to inflate and elevate the mountains of the deep, and thereby diffuse its waters, and level the furface of this earth. But when the vengeance of Omnipotence was finished, he commanded the sea and the waters to retire into their former refervoir; whereby the land appeared again, though not uniformly the fame as it was before; neither was it neceffary it should be so, so long as it was fufficient for all the purposes of life. At the fame time, the Father of Mercies left those remains of his power and juftice, to convince us by nature, as well as revelation, that he is able to do all things.

If we may have credit for this hypothefis, we are to believe also, that fome parts of the elevated deep returned to their first stations, and that others remained and became the present dry land, which was before the bottom of the sea; whereby we prefume to account for the appearances under the furface of St. Agnes beacon, and those distortions of the Strata, &c. in our parts, fome inclining one way, fome another, and fome quite reverfed. Neither will this elevation of the deep, and concomitant fubfidence of the land, appear unnatural to our idea of the matter, when we confider that the loftieft mountain upon the face of the earth, is not quite four miles in perpendicular height, which in fact amounts not to one fix thousandth part of its circumference; and bears not fo great a proportion to the bulk of the earth itself, as the little rifings on the coat of an orange bear to the bigness of that fruit.

There can be no doubt, that many alterations have happened to various parts of the earth, before, at, and after the flood, from inundations, earthquakes, and the diffolvent powers of fubterranean fire, and water; which variety of causes and circumstances muft infallibly have produced many irregularities

in the difpofition and fituation of circumjacent Strata and Lodes.

Having, as fuccinctly and clearly as I am able, delivered my own and other people's opinion upon these matters, I fhall, in the next place, proceed to examine the contents of thofe Fiffures and their properties; wherein a local and peculiar natural history will be so evident, that I shall hold myself excufable to fyftematick naturalifts, if I appear to them irregular and immethodical in the manner which I fhall take to purfue my fubject. As I have alfo fhewn the cause, nature, and variations of the Fiffure, I fhall in future make little use of that term; but in compliance with the custom of my country, fhall indiscriminately call a Fiffure, or its contents, the Lode: for instance, when I come particularly to define and defcribe the interruption and disorders of Lodes, I fhall fay that this or that Lode is heaved to the right, or to the left, up or down, by a cross Lode, a Contra, a Goffan, a Slide, a Flookan, or the like, pursuant to the idiom of our Miners; without taking notice of the Strata, upon which fuch alterations of Fiffures and their veiny fubftances depend.

We have ventured to advance the foregoing hypothefis, as the moft likely to account for those appearances which occur in the bowels of the earth; and we are not fingular in it, but are fupported by the concurrent opinion of fome very approved writers upon part of the same subject. And though we are fenfible that fome objections may be started against it; yet we can scarcely think, that those who may be most forward to deny it, are fupplied with one that will more rationally point out the causes of these appearances we fpeak of. As, however, we do not infift upon the infallibility of our fentiments, we shall submit them to the naturalift and philofopher with the greatest deference; and fhall be extremely glad to find, in our own day, the errors of our theory rectified by some abler pen.

CHAP.

CHA P. II.

Of the different kinds of Lodes in refpect of the Earth and Stones they contain.

TH

HE contents of our Fiffures are very complicated, and obtain their several diftinct appellations from the nature and appearance of the moft predominant Earth, Clay, Stone, or Mineral, contained in them; without any respect to the metallick impregnations of Tin, Copper, or Lead, unless the Ores of thofe Metals are very rich, and more abundant, than all the other contents of their Fiffures. The fame Lode, at higher or inferior levels, fhall be alternately named a Goffan, Mundick, or Flookany Lode, pursuant to their predominancy at twenty, forty, or fixty fathoms depth; or any other intermediate level they may offer to the obfervation of the Miners. Upon this account, moft Lodes take their names from the kind of Stone or Mineral they moft abound with, which often participates very largely of the nature of the Strata enclosing them.

The generality of our Lodes are very different to the eye and in their impregnation, near the furface, from what we find them when deeply funk upon; and though it has been known, that the backs of fome few veins have proved very rich, yet they do not always hold Metal, and frequently they do not carry Tin or Copper Ore enough to pay the charge of drefling or cleanfing them: nevertheless, in the finking upon fuch veins, we hope they will depart from their primary colour and appearance, and form large bodies of Tin or Copper Ore.

The flight metallick impregnations of our Lodes, which, especially in Copper, are generally observed to fifteen, and even thirty fathoms deep, must certainly arise from the scarcity of saline mineralick principles, which the water so near the surface cannot be largely faturated with; and having lefs depth of Strata to receive the metallick folutions from, they of neceffity cannot be furnished with ftrong menftrua, to act upon the Lodes, or depofite themselves. Although Mines are feldom discovered rich upon the backs, we prefume for the reasons before given ; yet experience will inform us, that they are fometimes well ftored with Copper and Tin Ores of the richest quality near the

day

day or furface; but this more frequent in the latter, though of no long continuance.

;

We shall divide Lodes which carry Tin, Copper, and Lead, into twelve different kinds, in regard to their foreign Materials and the removes vifible in them, we shall class into their proper fubdivifions. The Lodes are ranged in the following order:

I.

XI. A Flookan Lode.

A Grouan Lode.

Of all these Lodes, the Goffan is moft common; and is ever difpofed to yield Tin and Copper, if it runs east and weft; but those of a contrary direction, in respect of those Metals, are fteril and worthlefs. Goffan may not improperly be divided into five forts: viz. 1. a Tender Red Goffan; 2. a Tender Brown Goffan; 3. a Dry Pale Yellow Goffan; 4. a Poor Tin Goffan; and 5. a Gal or Gally Goffan: all of which are ochreish substances, of a rufty ferruginous complexion, being mostly Earth and Crystal coloured by Iron, with frequently no inconfiderable portion of that Metal.

I. The Tender Red Goffan is very much inclined to produce Copper Ore, especially if the Goffan be fpungy, cellular, and of a very red colour, like to a well burnt brick. When it is thus, and spotted, or tinctured with green Copper Ore, like pieces of Verdigrease, it does not often deceive the proprietors. So, likewife, Stones of blue or black Copper Ore, or of yellow Ore having a black or purple outside, are very hopeful to follow when mixed in this Goffan. Yet the Ore in this nidus is bunchy and uncertain, till proved to fome tolerable depth. But if Stones of Lead Ore be found in this Goffan, it promises well to produce a good quantity of Lead. This kind of Goffan was upon the back of Pednandrea Lode, and fome parts of Huel Sparnon, and is now very plentifully to be rifen at Michell's Goffan Mine, in Redruth.

2. A tender Brown Goffan, much of the colour of Iron, very brittle, and full of holes. The fmaller particles of it are of a brownish yellow, very crumbling, and fall to dust by long

exposure