In the weaving processes more specific measurement is possible, though even there much depends upon the quality of yarn that is used. Here a reduction in the working day is followed by an increase in speed without any labour-saving improvements. Previous to the Factory legislation of 1878, the speed of looms was generally from 170 to 190 picks per minute during the ten hours' day. In the course of about two years after the reduction of hours (6 per cent.) the general speed had become 190 to 200 picks, without change in machinery or raw material, a growth which must have proportionately increased the intensity of the work of weaving. A deterioration in the quality of the raw material used for producing cotton cloth is also commonly assigned as a fact involving more care on the part of the weaver, and increased danger and disagreeability of work owing to the heavy sizing and steaming it has brought into vogue. It is not easy to argue much respecting increased intensity of labour from the increased average of looms attended, for, as was recently admitted in evidence before the Labour Commission, everything depends upon the class of looms and of goods they are manufacturing. "It is quite as easy to drive five looms of some classes as two of others."[203] But the prevalence of the "driving" system, by which the overlookers are paid a bonus on the product of the looms under their charge, has admittedly induced, as it was obviously designed to do, an increased intensity of labour. Summing up the evidence, we are able to conclude that the shortening of working hours and the improvements in machinery has been attended by an increased effort per unit of labour time. In the words of an expert, "the change to those actually engaged in practical work is to lessen the amount of hard manual work of one class, but to increase their responsibility, owing to being placed in charge of more machinery, and that of a more expensive kind; while the work of the more lowly skilled will be intensified, owing to increased production, and that from an inferior raw material. I mean that to the operative the improvements in machinery have been neutralised by the inferior quality of raw material used, and I think it is fair to assume that their work has been intensified at least in proportion to the increase of spindles, etc." The direct evidence drawn from this most highly-evolved machine industry seems to justify the general opinion expressed by Professor Nicholson, "It is clear that the use of machines, though apparently labour-saving, often leads to an increase in the _quantity of labour_, negatively, by not developing the mind, positively by doing harm to the body."[204]