The President is authorized to employ so many of the public armed vessels as in his judgment the service may require, with suitable instructions to the commanders thereof in protecting the merchant vessels of the United States and their crews from piratical aggressions and depredations. (R. S., 4293.) The President is authorized to instruct the commanders of the public armed vessels of the United States to subdue, seize, take, and send into any port of the United States, any armed vessel or boat, or any vessel or boat, the crew whereof shall be armed, and which shall have attempted or committed any piratical aggression, search, restraint, depredation, or seizure, upon any vessel of the United States, or of the citizens thereof, or upon any other vessel; and also to retake any vessel of the United States, or its citizens, which may have been unlawfully captured upon the high seas. (R. S., 4294.) The commander and crew of any merchant-vessel of the United States, owned wholly, or in part, by a citizen thereof, may oppose and defend against any aggression, search, restraint, depredation, or seizure, which shall be attempted upon such vessel, or upon any other vessel so owned, by the commander or crew of any armed vessel whatsoever, not being a public armed vessel of some nation in amity with the United States, and may subdue and capture the same; and may also retake any vessel so owned which may have been captured by the commander or crew of any such armed vessel, and send the same into any port of the United States. (R. S., 4295.) Whenever any vessel, which shall have been built, purchased, fitted out in whole or in part, or held for the purpose of being employed in the commission of any piratical aggression, search, restraint, depredation, or seizure, or in the commission of any other act of piracy as defined by the law of nations, or from which any piratical aggression, search, restraint, depredation, or seizure shall have been first attempted or made, is captured and brought into or captured in any port of the United States, the same shall be adjudged and condemned to their use, and that of the captors after due process and trial in any court having admiralty jurisdiction, and which shall be holden for the district into which such captured vessel shall be brought; and the same court shall thereupon order a sale and distribution thereof accordingly, and at its discretion. (R. S., 4296.)