There never did exist on this earth a body of men wise enough to determine by any arbitrary rule how much currency is needed for the business of a great country. The laws of trade, the laws of credit, the laws of God impressed upon the elements of this world, are superior to all legislation; and we can enjoy the benefits of these immutable laws only by obeying them. * * * * * It has been demonstrated again and again that upon the artisans, the farmers, the day-laborers falls at last the dead weight of all the depreciation and loss that irredeemable paper-money carries in its train. Let this policy be carried out, and the day will surely and speedily come when the nation will clearly trace the cause of its disaster to those who deluded themselves and the people with what Jefferson fitly called "legerdemain tricks of paper-money." [Speech on the Railway Problem, June 22, 1874.] We are so involved in the events and movements of society that we do not stop to realize--what is undeniably true--that during the last forty years all modern societies have entered upon a period of change more marked, more pervading, more radical than any that has occurred during the last three hundred years. In saying this, I do not forget our own political and military history, nor the French Revolution of 1793. The changes now taking place have been wrought, and are being wrought, mainly, almost wholly, by a single mechanical contrivance, the steam locomotive. Imagine, if you can, what would happen if to-morrow morning the railway locomotive, and its corollary, the telegraph, were blotted from the earth. At first thought, it would seem impossible to get on at all with the feeble substitutes we should be compelled to adopt in place of these great forces. To what humble proportions mankind would be compelled to scale down the great enterprises they are now pushing forward with such ease! But were this calamity to happen, we should simply be placed where we were forty-three years ago. There are many persons now living who well remember the day when Andrew Jackson, after four weeks of toilsome travel from his home in Tennessee, reached Washington and took his first oath of office as President of the United States. On that day the railway locomotive did not exist. During that year Henry Clay was struggling to make his name immortal by linking it with the then vast project of building a national road--a turnpike--from the national capital to the banks of the Mississippi. In the autumn of that very year George Stephenson ran his first experimental locomotive, the "Rocket," from Manchester to Liverpool and back. The rumble of its wheels, redoubled a million times, is echoing to-day on every continent. * * * * *