A compendium of the practice of stating averages : for the use of counting-houses, insurance-brokers' offices, ship-owners, ship-masters, and others : consisting of an enumeration of the items in general average statements, and an appropriation of them to their respective columns : accompanied by copies of real average statements, by experienced adjusters of averages at Lloyd's : with a table to cover the premium, &c. : containing also, some new analysises and occasional observations on Mr. Stevens' essay on average, and other matters connected with marine insurance /