"The water frame, the carding engine, and the other machines which Arkwright brought out in a finished state, required both more space than could be found in a cottage, and more power than could be applied by the human arm. Their weight also rendered it necessary to place them in strongly-built walls, and they also could not be advantageously turned by any power then known but that of water. Further, the use of machinery was accompanied by a greater division of labour, and therefore a greater co-operation was requisite to bring all the processes of production into harmony and under a central superintendence."[60] Hence the growth of machine-production is to a large extent synonymous with the growth of the modern Factory System. § 3. Man does his work by moving matter. Hence machinery can only aid him by increasing the motive power at his disposal. (1) Machinery enables forces of man or nature to be more effectively applied by various mechanical contrivances composed of levers, pulleys, wedges, screws, etc. (2) Machinery enables man to obtain the use of various motor forces outside his body--wind, water, steam, electricity, chemical action, etc.[61] Thus by the provision of new productive forces, and by the more economical application of all productive forces, machinery improves the industrial arts. Machinery can increase the scope of man's productive ability in two ways. The difficulty of concentrating a large mass of human force upon a given point at the same time provides certain quantitative limits to the productive efficiency of the human body. The steam-hammer can perform certain work which is quantitatively outside the limit of the physical power of any number of men working with simple tools and drawing their motor power from their own bodies. The other limit to the productive power of man arises from the imperfect continuity of human effort and the imperfect command of its direction. The difficulty of maintaining a small, even, accurate pressure, or a precise repetition of the same movement, is rather a qualitative than a purely quantitative limit. The superior certainty and regularity of machinery enables certain work to be done which man alone could not do or could do less perfectly. The work of the printing machine could not be achieved by man. Machinery has improved the texture and quality of certain woollen goods;[62] recent improvements in milling result in improved quality of flour and so on. Machinery can also do work which is too fine or delicate for human fingers, or which would require abnormal skill if executed by hand. Economy of time, which Babbage[63] accounts a separate economy, is rightly included in the economies just named. The greater rapidity with which certain manufacturing processes--_e.g._, dyeing--can be achieved arises from the superior concentration and continuity of force possible under machinery. All advantages arising from rapid transport are assignable to the same causes.