_Difficulties encountered in locating the retreating enemy_--_Final determination upon pursuit_--_Lieutenant-Colonel Burke sets forth_--_Discovery of Spanish troops near Las Marias_--_A one-sided encounter_--_Unwelcome notification of truce_--_The rest of the brigade comes up_--_Feeding the prisoners_--_Our disappointment_. HEADQUARTERS INDEPENDENT BRIGADE (REGULARS), MAYACUEZ, PUERTO RICO, Aug. 22, 1898. GENERAL J.C. GILMORE, Headquarters of the Army, Ponce, P.R. _Sir_,--... Detachments from the cavalry troop went out (from Mayaguez) in the afternoon of the 11th on both roads leading to Lares; but the left hand or westerly of these roads was followed only a short distance, information, thought to be reliable, having been received to the effect that the bulk of the enemy's force had taken the more easterly road, on which the town of Maricao is situated. This part of the force was reported as making fair headway, having only a pack-train as transportation. Reports also came to brigade headquarters that Spanish troops in large numbers, coming from different places,--including Aguadilla and Pepino,--were concentrating to attack my command. While not impressed with the accuracy of these reports, I had the outposts strengthened, and placed a field officer in charge of them. A party from the outposts, sent to reconnoitre the Las Marias road, brought word on the afternoon of the 12th that the rear-guard of the Spanish was still within five miles of Mayaguez, and proceeding slowly. [Illustration: The Rosario River, near Hormigueros.]