In this case, if the cause had stood solely upon the evidence before the Circuit Court, we should have no difficulty in affirming its decision. But upon the new proofs which have been since taken, and are now produced to this Court, it is apparent that the capturing vessel was originally built, equipped, manned, and armed in the United States for a cruize, being owned by citizens of this country, and sailed with the intent of cruizing against Spain. It is true that she went to Buenos Ayres, and sailed under the colours of that government on a second cruize, during which this capture was made; but, there is no satisfactory evidence that the American ownership ever ceased, or that there was a real, bona fide sale at Buenos Ayres. If such a sale had really taken place, it was perfectly in the power of the captors to have proved it, in the clearest manner. A bill of sale is the customary and universal document by which the ownership of vessels is evidenced; and the want of any document of this nature, or of any direct and positive evidence of an actual sale, leaves no doubt in the mind of the Court, that no such sale ever was made. The consequence is, that the capturing vessel must still be considered, as owned in the United States; and, according to the decisions which have already been made, the capture was illegal, and the property must be restored to the original Spanish owners.