First Principles

Nor do the industrial and æsthetic Arts fail to supply us with equally conclusive evidence. The progress from rude, small, and simple tools, to perfect, complex, and large machines, illustrates not only a progress in heterogeneity and in definiteness, but also in integration. Among what are classed as the mechanical powers, the advance from the lever to the wheel-and-axle is an advance from a simple agent to an agent made up of several simple ones combined together. On comparing the wheel-and-axle, or any of the machines used in early times with those used now, we find an essential difference to be, that in each of our machines several of the primitive machines are united into one. A modern apparatus for spinning or weaving, for making stockings or lace, contains not simply a lever, an inclined plane, a screw, a wheel-and-axle, united together; but several of each integrated into one complex whole. Again, in early ages, when horse-power and man-power were alone employed, the motive agent was not bound up with the tool moved; but the two have now become in many cases fused together: the fire-box and boiler of a locomotive are combined with the machinery which the steam works.