This case comes before the court upon a writ of error to the Circuit Court of the United States for the district of Maryland. It is an action of indebitatus assumpsit, and was brought in the court below by the defendants in error, who were the original plaintiffs, to recover the freight earned by the ship Shirley on a charter of the ship made by the plaintiffs to the original defendants for the transportation of guano from the Chincha Islands to the United States. At the date of the charter-party, the defendants were the agents of the Peruvian Government, and, as such, had been for some time in the habit of chartering vessels to bring guano to the United States for sale. Its exportation from the islands is a Government monopoly, in which none except those employed by the Government are permitted to engage, and the defendants are the sole agents of that Government in the United States. They reside in Balitimore, and have agents in New York and Boston, duly authorized to negotiate for vessels, and, after the charters are signed by the owners, to transmit them to the defendants for their approval and signature. Their agents in Boston negotiated the charter of the Shirley, and, after it was executed in behalf of the owners, it was accordingly transmitted and signed by the defendants. It is dated Boston, April 11, 1854, and recites, among other things, that the Shirley was them lying at New York, and that she was to proceed to Callao, from Australia, where she was then bound, and from thence with all convenient dispatch to the Chincha Islands, to take in her cargo of guano. She was to be at Callao ready to load in the course of January and February, 1855, or sooner, and ninety running days were allowed for loading. After completing her loading, she was to proceed direct to Hampton Roads, her place of destination, to receive orders from the defendants or their agents to discharge at any safe port not south of Hampton Roads or north of Cape Ann. Freight was to be paid at the rate of twenty-five dollars per ton, custom-house weight, and the ship was to have the benefit of any advance in the guano freights made by the charterers in the United States before she finished loading at the islands.