If after the arrival of any vessel laden with merchandise and bound to the United States, within the limits of any collection-district, or within four leagues of the coast, any part of the cargo of such vessel shall be unladen, for any purpose whatever, before such vessel has come to the proper place for the discharge of her cargo, or some part thereof, and has been there duly authorized by the proper officer of the customs to unlade the same, the master of such vessel and the mate, or other person next in command, shall respectively be liable to a penalty of one thousand dollars for each such offense, and the merchandise so unladen shall be forfeited, except in case of some unavoidable accident, necessity, or distress of weather. In case of such unavoidable accident, necessity, or distress, the master of such vessel shall give notice to, and, together with two or more of the officers or mariners on board such vessel, of whom the mate or other person next in command shall be one, shall make proof upon oath before the collector, or other chief officer of the customs of the district, within the limits of which such accident, necessity, of distress happened, or before the collector, or other chief officer to the collection-district, within the limits of which such vessel shall first afterward arrive, if the accident, necessity, or distress happened not within the limits of any district, but within four leagues of the coast of the United States. The collector, or other chief officer, is hereby authorized and required to administer such oath. (R. S., 2867.) If any merchandise, so unladen from on board any such vessel, shall be put or received into any other vessel, except in the case of such accident, necessity, or distress, to be so notified and proved, the master of any such vessel into which the merchandise shall be so put and received, and every other person aiding and assisting therein, shall be liable to a penalty of treble the value of the merchandise, and the vessel in which they shall be so put shall be forfeited. (R. S., 2868.) Special permit to unlade by night and preliminary entry.