What Solon said to Croesus, when the latter was displaying his great treasures of gold, still holds true:--"If another comes that hath better iron than you, he will be master of all that gold." So, when an alchemist waited upon the Duke of Brunswick during the Seven Years' War, and offered to communicate the secret of converting iron into gold, the Duke replied:--"By no means: I want all the iron I can find to resist my enemies: as for gold, I get it from England." Thus the strength and wealth of nations depend upon coal and iron, not forgetting Men, far more than upon gold.
Thanks to our Armstrongs and Whitworths, our Browns and our Smiths, the iron defences of England, manned by our soldiers and our sailors, furnish the assurance of continued security for our gold and our wealth, and, what is infinitely more precious, for our industry and our liberty.
[1] "Mr.John Buchanan, a zealous antiquary, writing in 1855, informs us that in the course of the eight years preceding that date, no less than seventeen canoes had been dug out of this estuarine silt [of the valley of the Clyde], and that he had personally inspected a large number of them before they were exhumed.

Five of them lay buried in silt under the streets of Glasgow, one in a vertical position with the prow uppermost, as if it had sunk in a storm....

Almost every one of these ancient boats was formed out of a single oak-stem, hollowed out by blunt tools, probably stone axes, aided by the action of fire; a few were cut beautifully smooth, evidently with metallic tools.

Hence a gradation could be traced from a pattern of extreme rudeness to one showing great mechanical ingenuity....

In one of the canoes a beautifully polished celt or axe of greenstone was found; in the bottom of another a plug of cork, which, as Mr.Geikie remarks, 'could only have come from the latitudes of Spain, Southern France, or Italy.'"-- Sir C.LYELL, Antiquity of Man, 48-9.
[2] THOMAS WRIGHT, F.S.A., The Celt, The Roman, and The Saxon, ed.