(1) The physical weakness of woman, as compared with man, closes many occupations to her. In manufactures the metal industries have been almost entirely closed to women, and most branches of the mining and railway industries. In England and America the rougher work of agriculture is almost wholly given over to male labour, and in several continental countries there is a growing tendency to spare women the kinds of labour which tax the muscular forces most severely. The growing consideration for the duties of maternity, operating through public opinion and legislation, favour this curtailment of woman's sphere of activity. Further, in all employments where physical strength is an important factor, the net productivity of woman's labour tends to fall below man's, although in some cases superior deftness or lightness of hand related to physical fragility may compensate. Even in modern textile factories the superior force of man's muscles often gives him a great advantage. In fustian and velvet cutting, where the same piece-wages are paid to men and women, the actual takings of the men are about double. "Every person has two long frames upon which the cloth is stretched ready for cutting, and while women are unable to cut more than one piece at a time, men can cut two pieces without difficulty."[246] Where physical strength is not a prime factor it may enter incidentally. So even in weaving women are under some disadvantage through inability to work the heavy Jacquard looms, and to "tune" their looms.[247] Where manual work is concerned brute strength and endurance form an important ingredient in what is called manual skill, and affect the quality of the work as well as the pace and regularity of the output. Though, as we have seen, a chief object of modern machinery is to diminish the importance of this element, it plays no inconsiderable part in affecting the quantity of work turned out by women as compared with men even in industries where the direct strain upon the muscles is less severe.