(_a_). Industrial improvements tend to reduce wages. They do so, says Marx, through first mutilating the labourer intellectually and corporeally. As a result of subdivision of labour, workmen are rapidly becoming mere one-sided specialists. Headwork is being separated more and more from handwork in the labourer's occupation, and this differentiation of function leads to a hierarchy of wages which affords great opportunity for exploiting the labourer. Muscular power is more easily dispensed with than formerly, and so the cheaper labour of women and children is largely superseding the dearer labour of men. If this goes on much further, the manufacturer will get the labour of a whole family for the wages he used to pay to its head alone, and the labourer will be converted into a slave-dealer who sells his wife and children instead of his own labour. That this kind of slavery will find no sort of resistance from either master or labourer, is to Marx's mind placed beyond doubt by the fact that though the labour of children under 13 years of age is restricted in English factories, advertisements appear in public prints for "children that can pass for 13." (_b_). Industrial improvements tend to lengthen the day of labour. Machinery can go on for ever, and it is the interest of the capitalist to make it do so. He finds, moreover, a ready and specious pretext in the greater lightness of the work as compared with hand labour, for keeping the labourer employed beyond the normal limits of human endurance. Capitalists always complain that long hours are a necessity in consequence of the increasing extent of fixed capital which cannot otherwise be made to pay. But this is a mistake on their part, says Marx. For, according to the factory inspector's reports, shortening the day of labour to 10 hours has increased production and not diminished it, and the explanation is that the men can work harder while they are at it, if the duration of their labour is shortened. Shortening the day of labour has not only increased production, but actually increased wages. Mr. Redgrave, in his Report for 1860, says that during the period 1839-1859 wages rose in the branches of industry that adopted the ten hours' principle, and fell in trades where men wrought 14 and 15 hours a day. Small wages and long hours are always found to go together, because the same causes which enable the employer to reduce wages enable him to lengthen the labouring day.