The Dead Horse was sailor slang for the time required to work off the advance/signing fee. When a sailor signed on from a boarding house or as an independent, a month's advance on his salary was paid over. In theory, this money was to provide all the gear the sailor needed to have when coming aboard. When the month was over, he had worked off the dead horse and was working on his own account. In Bone's book, "Bowsprit Ashore," reference is made to a sailor who bragged about never having worked a full month in the packet trade.