It takes, reader, as you will have guessed, a very long journey indeed to knock into a traveller's head a complete conception of the size of North America. Mere space could never do it, for human nature is such that when trying to grasp in the mind any great lapse of time or territory, the two ends are brought together as it were, and all the great middle is forgotten. Nor does mere variety of scene emphasize distance on the memory, for the more striking details here and there crowd out the large monotonous intervals. Thus a mile of an Echo canyon obliterates half a state's length of Platte Valley pastures, and a single patch of Arkansas turtle-swamp whole prairies of Texan meadow. But in America, even though many successive days of unbroken travel may have run into one, or its many variations--from populous states to desert ones, from timber states to pasture ones, from corn states to mineral ones, from mountain to valley, river to lake, canyoned hills to herd-supporting prairies, from pine forest to oak forest, from sodden marsh to arid cactus-land--may have got blurred together, there grows at the end of it all upon the mind a befitting sense of vastness which neither linear measurement in miles nor variety in the panorama fully explain. It is due, I think, to the size of the instalments in which America puts forward her alternations of scene. She does not keep shifting her suits, so as to spoil the effect of her really strong hand, but goes on leading each till she has established it, and made each equally impressive. You have a whole day at a time of one thing, and then you go to sleep, and when you wake it is just the same, and you cannot help saying to yourself: "Twenty-four successive hours of meadowland is a considerable pasturage," and you do not forget it ever afterwards. The next item is twenty-four hours of mountains, "all of them rich in metals;" and by the time this has got indelibly fixed on the memory, Nature changes the slide, and then there is rolling corn-land on the screen for a day and night. And so, in a series of majestic alternations, the continent passes in review, and eventually all blends into one vast comprehensible whole. Apart from physical, there are curious ethnological divisions which mark off the continent into gigantic subnationalities. For though the whole is of course "American," there is always an underlying race, a subsidiary one so to speak, which allots the vast area into separate compartments. Thus on the eastern coast we have the mulatto, who gives place beyond Nebraska to the Indian, and he, beyond Nevada, to the Chinaman. After California comes the Mexican, and after him the negro, and so back to the East and the mulatto again.