Average. I. General (sometimes called gross or extraordinary), in mercantile.law, the contribution made by all the parties concerned in a sea adventure to make good an expense or loss sustained by one or more of them for the benefit of all. The fundamental principle of the law of general average, as expressed in Justinian's Pandects, and adopted by all commercial nations, though with considerable diversity of practice, comes from the Rhodian law, the first known system of marine law, which thus stated the rule: "If goods are thrown overboard in order to lighten a ship, the loss incurred for the sake of all shall be made good by the contribution of all." It would be difficult to set forth the essentials of a case for general average more clearly than they have been stated in the supreme court of the United States (Barnard v. Adams, 10 How. 270), Mr. Justice Grier delivering the opinion: "In order to constitute a case for general average, three things must concur: 1. A common danger, or a danger in which ship, cargo, and crew all participate - a danger imminent and apparently inevitable, except by voluntarily incurring the loss of a portion of the whole to save the remainder. 2. There must be a voluntary jettison, jactus, or casting away of some portion of the joint concern for the purpose of avoiding this imminent peril; or, in other words, a transfer of the peril from the whole to a particular portion of the whole. 3. This attempt to avoid a common peril must be successful.

The right to contribution is not made to depend on any real or presumed intention to destroy the thing cast away, but on the fact that it has been selected to suffer the peril in place of the whole that the remainder may be saved." Not only the value of the property destroyed, but what follows as a necessary consequence of its destruction, as injuries to other goods, expenses of refitting, and the wages and provisions of the crew in the port of relief, are subjects of contribution. So is also ransom paid to a pirate, by both the common and civil law (the rule of which on this point has been repealed in England), and in general whatever necessary and voluntary loss or expense is incurred by a part for the good of all. Goods finally saved must contribute for loss sustained in procuring temporary safety. By the French ordinance, goods stowed upon deck are expressly excluded from the benefit but not from the burden of general average, since they are supposed to hamper the vessel and increase the danger; and such is the general tenor of both the English and American law. In the courts of all three countries, however, an established usage to carry upon deck, as with small coasting vessels, is allowed to take a case out of the operation of the rule.

Both the continental and the American law is somewhat more liberal than the English as regards the subjects of general average, but the difference consists not in the nature but in the application of principles. The victuals and ammunition of a ship do not contribute in a case of general average, nor whatever is necessary to the persons of those on board, as wearing apparel, etc, nor the passengers for their own safety, nor the crew for their wages, lest apprehension of personal loss should deter them from personal sacrifice. The rule of the civil law that "those things alone which pay freight contribute" is, with slight limitations, the general law on this point. The rate of contribution is in proportion to the safety obtained, according to value, not weight. The rules upon which this adjustment is made differ in different countries, and are not well settled anywhere. It is a matter of such nice calculation, that in most commercial ports the computation and adjustment of general average constitute a special branch of business, attended to by a special class of men. By the civil law, the master of the vessel was required to see to this; and the provisions of the French ordinance are somewhat similar, but are practically disused, the work being performed by depecheurs, as they are called.

II. Particular, an almost obsolete barbarous expression, used to signify a partial loss, which must be borne by the immediate loser alone. III. Petty Averages are sundry small charges borne in common by the owners of a ship and cargo, like pilotage, towage, anchorage, light money, quarantine, etc.