第101章

None of the arts which are not necessary to the preservation of human existence itself, has probably bad greater influence on the modes which that existence has assumed, than metallurgy.Without the metals, it would be impossible for the series of instruments to be continued from which the wants of civilized society are supplied, and without them, consequently, mankind could never have emerged from barbarism.There are few arts, either, in which the processes have probably at first been more rude, in which they have ultimately attained greater perfection of skill, or in which the progress has been more gradual, and more dependent for its advance on the variety of the materials operated upon.Some metals are found in quantity pure, the ores of some are easily reduced, of others with great difficulty.Of all the substances he attempts to classify, none, from their number and variety, give greater trouble to the mineralogist.The discovery of the qualities of such portions of these metals as were found pure, would soon make them be considered as the most useful of substances, and occasion their being sought after with avidity.The supply of them in this state being exhausted, or they who had employed them moving into regions where they could no longer be found, recourse would gradually be had to the more pure and more easily reduced ores, and from thence to metals, and ores wrought with greater difficulty.Thus we find that gold, silver, and copper, the metals that most frequently occur native, were those first in use;iron came last, and was probably then esteemed the most precious.Weapons of gold and silver were edged with it, in the same manner as were wooden implements, such as the old English spade, in more recent days.But for the gentleness of the ascent, it is altogether likely, that the art would never have attained the eminence it has gained.Had the earth, for instance, possessed no metallic stores but the more abundant ores of iron, by far the most useful in the present days, it seems not unlikely, that no metal would ever have been wrought.The steps by which it rose, were, however, too numerous, and the vestiges left of them are too indistinct, for me to attempt here to trace them, were I even prepared so to do.I prefer rather, in illustration of the subject, to refer to an art which has been in practice for thousands of years, and to an implement in daily use.

The plough, in its most simple form, is an instrument, the invention of which would naturally follow the domestication of the ox species.Men accustomed to loosen, and stir the earth, with the inefficient implements of that ancient period, could scarce in time, fail to remark, that the sluggish strength of this animal might aid them in the operation.They seem to have turned it to this purpose, by a very simple contrivance.Along crooked sapling, similar to the clubs used by boys in some of their games, but larger, had its thick, curved end, sharpened to a point, and its other extremity attached to something like what is now called a yoke, coupling two oxen by the neck.The long straight part of the implement, passed between the animals, the part turned downwards rested on the earth behind them, and when they moved forward, along soil very easily impressed, would mark it with a furrow, which might be deepened by a man walking close after, and pressing it downwards.He was assisted in this operation, by the addition of a handle projecting upwards, the point was hardened by the action of the fire, and another person guided the oxen.Such was probably the earliest plough, and those that are used in many parts of the east, to this day, differ not much from it, with the exception of the point being defended by a sort of iron tooth, and the wood not having a natural, but an artificial curvature.In Java, a man, when he has done his day's work, carries home his plough on his shoulder, as a woodman does his axe.The defects of such an implement are to us very plain.It only scratches the soil, it cannot make what we call a furrow, and it is only very light, sandy soil, or the sort of mud, in which rice is cultivated, on which it is at all capable of acting.As the quantity of this sort of soil is, in all parts of the world limited, men were gradually forced to attempt the tillage of land more difficult to subdue.Over the greater part of Asia, they have done so, by a simple enlargement and strengthening of the first rude implement.The model immediately before their eyes seems to have so confined their powers of invention, that they attempted no change but this.

In that part of the world, if we except China, and the countries bordering on Europe, the earth is consequently scratched, or at best stirred, it is not in our sense of the word ploughed.The improvements which we have made in the operation are two fold; the first concerns the effect produced on the soil, and the second, the ease with which it is produced.The furrow we form makes each portion of soil operated upon, describe about one third of a circle, thus blending all the parts of the surface together, leaving it very open, and placing the vegetable fibres in the position best suited to induce decay.The turn too, thus given, to each portion, puts it out of the way of the next, which is therefore, with comparative ease, moved into its proper position.

It seems not to have been, until the instrument got to Europe, that it assumed a form capable of executing such an operation.Such was probably the Roman plough, the wood-work of which is thus described by Virgil.

"Continuo in sylvis magna vi flexa domatur In burim, et curvi formam aceipit ulmus aratri, Huci a stirpe pedes temo protentus in octo, Binae aures, duplici aptantur dentalia dorso.

Caeditur et tilia ante jugo levis, altaque fagus, Stiraqae, qum curtuna tergo torqueat imos;Et suspensa focis exptorat robora fumus.