Section 308
SEC. 308. If the gross weight of any article or package described in the manifest of an importing vessel is found to exceed by more than ten per centum the gross weight as declared in the manifest or bills of lading thereof, a penalty not exceeding twenty-five dollars and an amount equal to ten per centum of the value thereof for each such package or article shall he imposed upon the master of the importing vessel, unless it shall he established to the satisfaction of the collector by the master or consignee that such excess of weight was the result of mistake and without fraud.