The superior workman earns indeed better pay working by the piece, but the general body do not. The superior workman can afford to take a smaller price per piece than the others, because he turns out a greater number of pieces in the same time, and the employer fixes, from the case of the superior workman, a standard of payment which is injurious to the rest. In the end a change from day's wages to piece wages will thus be found to have merely resulted in the average labourer working harder for the same money. Marx, however, admits that when a definite scale of prices has been in long use and has become fixed as a custom, there are so many difficulties to its reduction that employers are obliged, when they seek to reduce it, to resort to violent methods of transforming it into time wages again. He gives an example of this from the strike of the Coventry ribbon-weavers in 1860, in resistance to a transformation of this kind. These are only some of the evils Marx lays at the door of piecework; he has many more charges. From rendering the superintendence of labour unnecessary, it leads to abuses like the sub-contracts known in this country as "the sweating system," or what is a variety of the same, to contracts of the employer with his manager, whereby the latter becomes responsible for the whole work, and employs and pays the men. From making it the pecuniary interest of the labourer to work overtime, piecework induces him to overstrain his powers, and both to transgress the legal or normal limits of the day of labour, and to raise or exceed the normal degree of the intensity of labour. Marx, quoting from Dunning, says that it was customary in the engineering trade in London for employers to engage a foreman of exceptional physical powers, and pay him an extra salary per quarter to keep the men up to his own pace; an expedient which, he adds, is actually recommended to farmers by Morton in his "Agricultural Encyclopædia." He attributes to piecework, especially in its operation on women and children, the degeneration of the labouring class in the potteries, which is shown in the Report of the Commission on the Employment of Children. But while Marx thus objects to piecework because it leads to overwork, he objects to it also because it leads to underwork. It enables employers to engage more hands than they require, when they entertain perhaps only an imaginary expectation of work, for they know they run no risk, since paying by the piece they pay only for what is done. The men are thus imperfectly employed and insufficiently paid.