primage

from The Collaborative International Dictionary of English v.0.48

Primage \Pri"mage\ (?; 48), n. [F.] (Com.)
   A charge in addition to the freight; originally, a gratuity
   to the captain for his particular care of the goods
   (sometimes called {hat money}), but now belonging to the
   owners or freighters of the vessel, unless by special
   agreement the whole or part is assigned to the captain.
   --Homans.
   [1913 Webster]

from Bouvier's Law Dictionary, Revised 6th Ed (1856)

PRIMAGE, merc. law. A duty payable to the master and mariner of a ship or 
vessel; to the master for the use of his cables and ropes to discharge the 
goods of the merchant; to the mariners for lading and unlading in any port 
or haven. Merch. Dict. h.t.; Abb. on Ship. 270. 
     2. This payment appears to be of very ancient date, and to be variously 
regulated in different voyages and trades. It is sometimes called the 
master's hat money. 3 Chit. Com. Law, 431.