Fragment of Letter to -------, 1891: 

. . . .  I confine myself to life with which I am familiar when pretending to portray life.  But I confined myself to the boy-life out on the Mississippi because that had a peculiar charm for me, and not because I was not familiar with other phases of life.  I was a soldier two weeks once in the beginning of the war, and was hunted like a rat the whole time.  Familiar?  My splendid Kipling himself hasn’t a more burnt-in, hard-baked, and unforgetable familiarity with that death-on-the-pale-horse-with-hell-following-after, which is a raw soldier’s first fortnight in the field—­and which, without any doubt, is the most tremendous fortnight and the vividest he is ever going to see.

Yes, and I have shoveled silver tailings in a quartz-mill a couple of weeks, and acquired the last possibilities of culture in that direction.  And I’ve done “pocket-mining” during three months in the one little patch of ground in the whole globe where Nature conceals gold in pockets—­or did before we robbed all of those pockets and exhausted, obliterated, annihilated the most curious freak Nature ever indulged in.  There are not thirty men left alive who, being told there was a pocket hidden on the broad slope of a mountain, would know how to go and find it, or have even the faintest idea of how to set about it; but I am one of the possible 20 or 30 who possess the secret, and I could go and put my hand on that hidden treasure with a most deadly precision.

And I’ve been a prospector, and know pay rock from poor when I find it —­just with a touch of the tongue.  And I’ve been a silver miner and know how to dig and shovel and drill and put in a blast.  And so I know the mines and the miners interiorly as well as Bret Harte knows them exteriorly.

And I was a newspaper reporter four years in cities, and so saw the inside of many things; and was reporter in a legislature two sessions and the same in Congress one session, and thus learned to know personally three sample bodies of the smallest minds and the selfishest souls and the cowardliest hearts that God makes.

And I was some years a Mississippi pilot, and familiarly knew all the different kinds of steam-boatmen—­a race apart, and not like other folk.

And I was for some years a traveling “jour” printer, and wandered from city to city—­and so I know that sect familiarly.

And I was a lecturer on the public platform a number of seasons and was a responder to toasts at all the different kinds of banquets—­and so I know a great many secrets about audiences—­secrets not to be got out of books, but only acquirable by experience.

And I watched over one dear project of mine for years, spent a fortune on it, and failed to make it go—­and the history of that would make a large book in which a million men would see themselves as in a mirror; and they would testify and say, Verily, this is not imagination; this fellow has been there—­and after would cast dust upon their heads, cursing and blaspheming.