The strangeness of the undertaking is no less pronounced than the rigour of its obligations. Mark Twain began his career as a professional humorist and fun-maker; he frankly donned the motley, the cap and bells. The man-in-the-street is not easily persuaded that the basis of the comic is, not uncommon nonsense, but glorified common-sense. The French have a fine-flavoured distinction in _ce qui remue_ from _ce qui emeut_; and if _remuage_ is the defining characteristic of 'A Tramp Abroad', 'Roughing It', and 'The Innocents Abroad', there is much of deep seriousness and genuine emotion in 'Life on the Mississippi', 'Tom Sawyer', 'Huckleberry Finn', and 'Pudd'nhead Wilson'. In the course of his lifetime, Mark Twain evolved from a fun-maker into a masterly humorist, from a sensational journalist into a literary artist. In explanation of this, let us recall the steps in that evolution. In his youth, this boy had no schooling worth speaking of; he lived in an environment that promised only stagnation and decay. As the young boy, barefooted and dirty, watched the steamboats pass and repass upon the surface of that great inland deep, the Mississippi, he conceived the ambition and the ideal of learning to know and to master that mysterious water. His dream, in time, was realized; he not only became a pilot, but--which is infinitely more significant--he changed from a callow, indolent, unobservant lad, with undeveloped faculties, to a man, a master of the river, with a knowledge which, in its accuracy and minuteness, was, for its purpose, all-sufficient and complete. I have always felt that, had it not been for this training in the great university of the Mississippi, Mark Twain might never have acquired that trained faculty for minute detail and descriptive elaboration without which his works, full of flaws as they are, might never have revealed the very real art which they betray. For the art of Mark Twain is the art of taking infinite pains--the art of exactitude, precision and detail. Humour per se is as ephemeral as the laugh--dying in the very moment of its birth. Art alone can give it enduring vitality. Mark Twain's native temperament, rich with humour and racy of the soil, drank in the wonder of the river and unfolded through communication with all its rude human devotees; the quick mind, the eager susceptibility, developed and matured through rigorous education in particularity and detail; and before his spirit the very beauties of Nature herself disappeared in face of a consuming sense of the work of the world that must be done.