The investigation of principles is quickly followed by practical inventions. This, indeed, is the characteristic feature of our times. It has produced a great revolution in national policy.
In former ages wars were made for the procuring of slaves. A conqueror transported entire populations, and extorted from them forced labor, for it was only by human labor that human labor could be relieved. But when it was discovered that physical agents and mechanical combinations could be employed to incomparably greater advantage, public policy underwent a change; when it was recognized that the application of a new principle, or the invention of a new machine, was better than the acquisition of an additional slave, peace became preferable to war. And not only so, but nations possessing great slave or serf populations, as was the care in America and Russia, found that considerations of humanity were supported by considerations of interest, and set their bondmen free.
SCIENTIFIC INVENTIONS. Thus we live in a period of which a characteristic is the supplanting of human and animal labor by machines. Its mechanical inventions have wrought a social revolution. We appeal to the natural, not to the supernatural, for the accomplishment of our ends. It is with the "modern civilization" thus arising that Catholicism refuses to be reconciled. The papacy loudly proclaims its inflexible repudiation of this state of affairs, and insists on a restoration of the medieval condition of things.
That a piece of amber, when rubbed, will attract and then repel light bodies, was a fact known six hundred years before Christ. It remained an isolated, uncultivated fact, a mere trifle, until sixteen hundred years after Christ. Then dealt with by the scientific methods of mathematical discussion and experiment, and practical application made of the result, it has permitted men to communicate instantaneously with each other across continents and under oceans. It has centralized the world. By enabling the sovereign authority to transmit its mandates without regard to distance or to time, it has revolutionized statesmanship and condensed political power.
In the Museum of Alexandria there was a machine invented by Hero, the mathematician, a little more than one hundred years before Christ. It revolved by the agency of steam, and was of the form that we should now call a reaction-engine. This, the germ of one of the most important inventions ever made, was remembered as a mere curiosity for seventeen hundred years.
Chance had nothing to do with the invention of the modern steam-engine. It was the product of meditation and experiment. In the middle of the seventeenth century several mechanical engineers attempted to utilize the properties of steam; their labors were brought to perfection by Watt in the middle of the eighteenth.
The steam-engine quickly became the drudge of civilization. It performed the work of many millions of men. It gave, to those who would have been condemned to a life of brutal toil, the opportunity of better pursuits. He who formerly labored might now think.
Its earliest application was in such operations as pumping, wherein mere force is required. Soon, however, it vindicated its delicacy of touch in the industrial arts of spinning and weaving. It created vast manufacturing establishments, and supplied clothing for the world. It changed the industry of nations.
In its application, first to the navigation of rivers, and then to the navigation of the ocean, it more than quadrupled the speed that had heretofore been attained. Instead of forty days being requisite for the passage, the Atlantic might now be crossed in eight. But, in land transportation, its power was most strikingly displayed. The admirable invention of the locomotive enabled men to travel farther in less than an hour than they formerly could have done in more than a day.
The locomotive has not only enlarged the field of human activity, but, by diminishing space, it has increased the capabilities of human life. In the swift transportation of manufactured goods and agricultural products, it has become a most efficient incentive to human industry