that stock of substantial learning in the effort to develop the resources of nature for use; and such advances could only go on, unimpeded, after the nature of the great sources of power in the world should have been discovered and their availability for the purposes of the engineer recognized. Mechanical engineering, as we understand it, could only fairly start in its wonderful progress after the mechanic had found ways of utilizing natural forces and energies, and of making the tools with which to produce these prime motors, through the operation of which all the arts could be given application in the production of wealth, multiplying the power of the unaided hand by making it in the performance of work the guide of greater powers, rather than the tool itself. It was only when mighty powers could be thus developed and guided and directed that mighty tasks could be performed by so weak and insignificant an organism as man. Man as a prime mover is feeble and helpless before the great powers of nature; man as the master and guide of nature's powers is only less than omnipotent.
Mechanical engineering, to achieve its highest tasks, must have control of the grandest powers of nature and of all her energies; it must avail itself of prime movers transforming all actual and potential energies into available, transformable, useful work; it must be capable of making for itself tools and machines and apparatus, scientific and other, competent to direct those energies in definite and helpful ways to the performance of every useful task. Progress must wait for the power and power must be guided, divided, applied, through invention and the mechanic arts, to defined and precisely related productive operations. The natural order is: first, sources of available energies; second, prime movers applying while developing those energies; third, tools and machines devised and constructed to perform detailed tasks, exactly and perfectly. Invention is the first necessity, and necessity has been found to be the mother of invention; but invention is helpless without tools, and invention began with the first crude tools; the motors followed, and better tools followed motors, and better motors followed the invention of better tools. It was only a century ago, or a little more, when the inventor had reached a certain stage in the production of tools, that Watt could produce the steam engine of the nineteenth century, that a system of manufactures could come into being as the fruit of invention and that the Golden Age of the centuries could begin.
The Golden Age of the World, in all good senses, had its origin with the birth of the nineteenth century, and when mechanical engineering began uniting all the sciences and all the arts into one great system of adaptation of nature's powers to the work of the promotion of civilization. This fairly begun, the steam-engine, the gas-engine, the electric motors and generators, telegraphs and telephones, the steamboat, the locomotive, the automobile, textile manufactures, iron and steel