xix. No bog iron has been found in proximity to any of the remains of

ironworks; probably the iron-smelters consumed all that was conveniently near the scenes of their operations. In the neighbourhood of all the remains of ironworks in Gairloch are found ferruginous rocks and shales, or rust-coloured earths. The best samples of these rocks have on analysis yielded but eight per cent. of metallic iron, and the rust-coloured earths are by no means rich in the metal. But there can be no doubt that bog iron was formerly present in the vicinity of these rocks, shales, and earths; and the analyses of the ancient iron slags prove to demonstration that such bog iron was the ore used at the ancient bloomeries.

Mr W. Ivison Macadam, analytical chemist of Edinburgh, is hopeful that the analyses he has undertaken may in course of time throw more light on the methods and productions of the ancient ironworkers. It is not probable that we shall ever know much of their history. According to the Rev. Donald M'Nicol they made iron "in the blomary way, that is by laying it under the hammers in order to make it malleable, with the same heat that melted it in the furnace." In the present day the processes of smelting iron and of producing malleable iron are separate and distinct; these ancient artisans probably combined the two. The slags produced at their furnaces contained a large proportion of metallic iron. Mr Macadam has found fully fifty per cent. of iron in most of the samples of ancient Gairloch slags he has analysed, and at some modern ironworks quantities of ancient slag have actually been found worth resmelting. The wasteful richness of the old slags can be easily accounted for; the ancient methods of smelting were comparatively imperfect, labour was cheap, the iron used cost nothing, and the forests whence was derived the charcoal for smelting it were apparently inexhaustible, whilst the business was no doubt carried on more for the supply of local and immediate wants than as a branch of commerce. If the ironworkers could obtain by their primitive processes enough iron to supply their own requirements, they would naturally be careless of the amount of metal wasted.

The fuel universally used for iron-smelting, until far into the eighteenth century, was wood-charcoal, and even to the middle of the nineteenth century it was still employed at two blast-furnaces in Scotland. Every part of the Highlands, not excepting the parish of Gairloch, was clothed with dense forests of fine timber. Far up the mountain slopes, and down to the rocky shores of the sea, the fir, oak, and birch flourished in wonderful and beautiful profusion. There is no poetic license, no picturesque exaggeration in this statement. Everywhere the relics of trees are to be seen to this day, and much of the timber used by Gairloch crofters in roofing their dwellings and for other purposes consists of branches found underground. The disappearance of the great Caledonian forest has been accounted for in several ways; some have conjectured that a vast conflagration or series of conflagrations destroyed it; others think that its destruction was more gradual, and resulted from the labours of the charcoal burners and similar doings. In Gairloch there are charred stumps still to be seen preserved in peat bogs, that support the conflagration theory; but there is also widespread evidence of extensive charcoal burnings, so that there must be some truth in both these modes of accounting for the destruction of the woods. Some localities of charcoal burnings will be mentioned in Part I., chap. xx.

All the ancient Gairloch ironworks are in the vicinity of burns. This fact raises a strong inference that the older ironworkers, like their historic successors, utilised the water-power afforded by adjoining streams for the purpose of working machinery. The Rev. D. M'Nicol's statement, already quoted, that hammers were used to produce malleable iron confirms the inference; and the remains of dams or weirs, and other expedients for augmenting the water-power, convert the conjecture into an established fact. It appears certain, then, that heavy hammers worked by machinery, with water for the motive power, were used in remote times,--another testimony to the ingenuity and mechanical skill of the ancient inhabitants of the Highlands. The tuyere for a furnace-blast found at Fasagh (_see illustration_) is another evidence of that skill.

The reader must please remember that the ancient ironworks referred to in this chapter are quite distinct from the historic series to which our next is devoted.