In these curved lines and smoothness, in this perfect adaptability of means to end, there is the spirit of art showing itself, not with colour or crayon, but working in tangible material substance. The makers of this plough--not the designer--the various makers, who gradually put it together, had many things to consider. The fields where it had to work were, for the most part, on a slope, often thickly strewn with stones which jar and fracture iron. The soil was thin, scarce enough on the upper part to turn a furrow, deepening to nine inches or so at the bottom. So quickly does the rain sink in, and so quickly does it dry, that the teams work in almost every weather, while those in the vale are enforced to idleness. Drain furrows were not needed, nor was it desirable that the ground should be thrown up in "lands," rising in the centre. Oxen were the draught animals, patient enough, but certainly not nimble. The share had to be set for various depths of soil. All these are met by the wheel plough, and in addition it fulfils the indefinite and indefinable condition of handiness. A machine may be apparently perfect, a boat may seem on paper, and examined on principles, the precise build, and yet when the one is set to work and the other floated they may fail. But the wheel plough, having grown up, as it were, out of the soil, fulfils the condition of handiness. This handiness, in fact, embraces a number of minor conditions which can scarcely be reduced to writing, but which constantly occur in practice, and by which the component parts of the plough were doubtless unconsciously suggested to the makers. Each has its proper name. The framework, on wheels in front--the distinctive characteristic of the plough--is called collectively "tacks," and the shafts of the plough rest on it loosely, so that they swing or work almost independently, not unlike a field-gun limbered up.