Early in the afternoon of the 2d of January, 1857, the Sierra Nevada arrived at San Juan del Sur from San Francisco. Her passengers were in a few hours aboard of the San Carlos ready to cross the lake. Some anxiety had been felt at Rivas on account of the long delay of the La Virgen in the river, but it was easy to imagine causes why she had not yet returned to Virgin Bay. Therefore the steamer San Carlos, with the passengers aboard, unsuspectingly approached Fort San Carlos and passed into the river without seeing any cause for alarm on shore. But when the steamer had passed the fort, Spencer, who was aboard a river boat with a force of Costa Ricans, hailed the San Carlos, demanding her surrender. There were a number of Nicaraguan officers on the San Carlos, going to the United States, but in the midst of the confusion, created by the surprise, Spencer got aboard of the lake steamer and soon had possession of her. The captain of the San Carlos, a cool, bold Dane, proposed to run the steamer back into the lake under the guns of the fort, and the movement might have been made without any great danger or loss of life. But Harris, jointly interested with his father-in-law, Morgan, in the transit contract across Nicaragua, happened to be aboard the steamer, and he refused to permit Capt. Ericsson to make the attempt. By the surrender of the San Carlos the Costa Ricans got control of the lake, and thus they were enabled to communicate rapidly and readily with the Allies at Masaya, while Walker was cut off from any direct communication with the Caribbean sea. It is clear that the success of Mora’s movement to the San Juan river was due to the skill and daring of Spencer. The march to the San Carlos with all its expense and all its fatigues would have been useless without the aid of the bold hand which got possession of the river steamers. And the success of Spencer was the reward of a rashness which, in war, sometimes supplies the place of prudent design and wise combinations. The fortune which proverbially favors the brave certainly aided Spencer much in his operations. Mora afterward Attempted to depreciate the value of the services Spencer rendered him; and the brutality of the man toward the soldiers soon made it an object for the Costa Rican General to get rid of him. But it would be difficult to overestimate the advantages the Allies derived from the services of the base and murderous man who did not scruple for the sake of lucre to imbrue his hands in the blood of countrymen straggling to maintain the rights of their race against a cruel and vindictive foe.