`` mr. hammond , '' he said , very quiet but with authority , more authority than laurence , who for most of their acquaintance had known him as a subordinate , had ever heard him use ; an authority which quite cleared away all traces of his ordinary easy-going humor , `` pray convey to the chinamen that it is essential they stay below ; i do not give a damn what excuse you like to give them , but i would not wager tuppence for their lives if they came on this deck now .