It is a part of the contract.  Yet there has grown up in merchant vessels a series of customs, which have become a well-understood system, and have somewhat the force of prescriptive law.  To be sure, all power is in the captain, and the officers hold their authority only during his will, and the men are liable to be called upon for any service; yet, by breaking in upon these usages, many difficulties have occurred on board ship, and even come into courts of justice, which are perfectly unintelligible to any one not acquainted with the universal nature and force of these customs.  Many a provocation has been offered, and a system of petty oppression pursued towards men, the force and meaning of which would appear as nothing to strangers, and doubtless do appear so to many ``’long-shore’’ juries and judges.

The next little diversion was a battle on the forecastle, one afternoon, between the mate and the steward.  They had been on bad terms the whole voyage, and had threatened a rupture several times.  Once, on the coast, the mate had seized the steward, when the steward suddenly lowered his head, and pitched it straight into Mr. Brown’s stomach, butting him against the galley, grunting at every shove, and calling out ``You Brown!’’ Mr. Brown looked white in the face, and the heaviest blows he could give seemed to have no effect on the negro’s head.  He was pulled off by the second mate, and Mr. Brown was going at him again, when the captain separated them; and Mr. Brown told his tale to the captain, adding ``and, moreover, he called me Brown!’’ From this time ``moreover, he called me Brown,’’ became a by-word on board.  Mr. Brown went aft, saying, ``I’ve promised it to you, and now you’ve got it.’’ But he did not seem to be sure which had ``got it’’; nor did we.  We knew Mr. Brown would not leave the thing in that equivocal position all the voyage, if he could help it.  This afternoon the mate asked the steward for a tumbler of water, and he refused to get it for him, saying that he waited upon nobody but the captain; and here he had the custom on his side.  But, in answering, he committed the unpardonable offence of leaving off the handle to the mate’s name.  This enraged the mate, who called him a ``black soger,’’ and at it they went, clenching, striking, and rolling over and over; while we stood by, looking on and enjoying the fun.  The darkey tried to butt him, as before, but the mate got him down, and held him, the steward singing out, ``Let me go, Mr. Brown, or there’ll be blood spilt!’’ In the midst of this, the captain came on deck, separated them, took the steward aft, and gave him half a dozen with a rope’s end.  The steward tried to justify himself, but he had been heard to talk of spilling blood, and that was enough to earn him his flogging; and the captain did not choose to inquire any further.  Mr. Brown was satisfied to let him alone after that, as he had, on the whole, vindicated his superiority in the eyes of the crew.