Ps were owners of a ship called the Tarleton. P fitted out the ship with hopes of trading with the natives on the Cameroon coast. The captain of the Tarleton sent a smaller vessel called the Bannister loaded with goods to another part of the coast to trade with natives. Natives began to visit the Bannister when D's ship the Othello shot on them with cannon killing one of them. P alleged that D did this so that the natives would not trade with P. P called the commander of the Bannister to testify at trial and the facts as stated were so proved. On cross-examination, it was admitted that by custom, no Europeans can trade until a duty was paid to the king of that country and that P had not paid that duty. D contended that P was engaged in illicit trade and that the law should not support his cause of action.