Whether this equipofe in the profit and lofs, is a fact, or only a falfe allegation, I will not take upon me to say; but if they be not tantamount to each other, we verily believe upon the whole, the gain is far fhort of that recompence which is due to the refolution and fedulous pursuit of the Mine Adventurers in Cornwall.

Suppofing the proceeds in Tin and Copper to be annually four hundred thousand pounds, and the feparate gain being aggregate; upon a dividend of twelve and a half cent. it will come out fifty thoufand pounds, which is only a profit of oneeighth upon the certain rifk of fo large a fum: but those who are converfant in Mining, we are well affured, would be very happy if they could promise themselves only feven blanks to one prize, which from unlucky experience we know to be not the cafe, and that nineteen blanks to a prize, will more nearly quadrate with the truth of the matter, by which our former dividend is reduced to five cent. and the grofs gain to only twenty thousand pounds annum.

This, however, makes fome profit appear; but how small, if true! how inadequate to the fum laid out and expended! This fhews the infatuation, and delufive hopes of political gaming, under which ftigma it apparently lies. We shall forbear any further reflections upon the fubject, left we incur the blame and reproach of our neighbours and countrymen; but as we write for the publick eye, we find it neceffary to relate facts as they occur, whether they are unpleafing to the interested or not. In purfuance of which determination, we hope the landholders will hold us excufable, when we affert upon the cleareft conviction, that they contribute by their heavy exactions to deprive the induftrious adventurers of too large a proportion of that profit, which ought to be applied for the encouragement and reward of their arduous and expenfive undertakings. At a medium, the Lords of the foil have one-feventh part clear from all expence now the one-feventh of four hundred thoufand pounds, being fifty-feven thousand one hundred and forty-two pounds, it appears, by a ftriking comparison, for whom the Mines are wrought, and who are the principal gainers thereby; and very completely accounts for the great complaisance, candour, gratitude, and generosity of those gentlemen, to the several Adventurers in their refpective eftates.

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At

At this time, when all the neceffaries of life are high in value, the price of all manner of materials advanced, the wages of labourers from a natural confequence proportionably increased, the price for Tin funk down from three pounds ten fhillings to three pounds, and Copper Ore fallen more than thirty cent. below the true ftandard, have we not great reafon to fear the event of fuch combined and adverfe caufes to the profperity of this county? Is it not alarming? And how fhall we account for all that fupinenefs which is manifefted by thofe, whose interest and business it should be to mitigate the recited diftreffes of a laborious and ufeful community?

Government would reap a very fruitful harvest annually, from a fuitable encouragement of the Mining interest in Cornwall. We believe, if the managers of publick affairs would leffen fome of the heavy duties upon our materials, and wholly remit others, fuch indulgence would operate as a bounty, and greatly multiply our contributions to the national revenue, by animating the Mine Adventurers to rework feveral deep expenfive Mines, now dormant through the great preffure of weighty impofts, upon the back of many natural difficulties and obftructions.

The drawback upon coal used in our smelting-houses and fire engines, has been attended with fuch happy confequences for the publick, that we may venture to affirm, not one-fifth of the fire fteam engines now working, would ever have been erected without fuch encouragement. Thirty-fix years ago, this county had only one fire engine in it: fince which time above three score have been erected, and more than half of them have been rebuilt, or enlarged in the diameter of their cylindrical dimenfions.

We shall leave the publick to reflect and animadvert upon this notorious truth.

An Account of all the Copper Ores fold in Cornwall the last fifty Years; their Tonnage, Amount, Price, and Value.

Date Ann. Tonnage Date (Ann. Tonnage Date |Ann. Tonnage

A

GENERAL TREATISE

UPON

MINERALS, MINES,

AND

MINING.

BOOK I.

С НА Р. I.

Of the Origin and Formation of Metals and Minerals.

F

ROM the invifibility of the original caufes of Minerals and Metals, every system and theory, framed to account for their production, must be fpeculative and controvertible. The mundane theories of Burnet, Woodward, Whifton, De la Prime, Scheuzer, and others, though they have all their probabilities, are all liable to many objections. Indeed, to fearch into the fecret caufes of feveral appearances in nature that are evidently exifting, and obvious to our fenfes, both in her grofs and minute operations, requires fo much accurate labour, found learning, and folid judgment, that as it would appear prefumptuous in me to obtrude any particular theory of my own, I fhall only offer my opinion in the following sheets, with all imaginable deference to the judgment of the candid publick.

Though the ftupendous views we have of divine architecture, fill our fouls with admiration and aftonishment at his power who framed the heavens, and laid the foundations of