“ Mr. Hubley Ashton, counsel of the appellant, now filed an affidavit of that party, stating that since the taking and perfecting of the appeal he had learned that two of the witnesses for the schooner in the District Court, the master and the mate of that vessel, had received from the libellant, John Low, Jr., before giving their testimony, an agreement for the payment of a sum of money on the contingency and in the event that the case should be decided in favor of the libellant and he should receive the damages claimed. ”