without effect, by the enemy’s scouts, who were concealed behind a hedge lining the Hormigueros road.  They were easily dispersed.  The infantry and advance-guard having passed this point, the cavalry took the latter road, and, crossing the Rosario, turned westward, and advanced under cover of the railroad embankment until—­taking every opportunity to damage the enemy by its fire action—­it reached a position beyond the covered wooden bridge.

[Illustration:  Guenar Bridge, Mayaguez.]

The brigade commander had left San German at the head of the main body.  When he heard the firing in his front, he sent word to commanding officers to advance without further halt, and to keep their commands closed up.  Similar orders were sent to the train.  He was informed and approved of the route taken by the cavalry before reaching the bridge.  He crossed the latter about half-past three o’clock, being at that time about 500 yards in advance of the main body.

[Illustration:  Upper End of the Calle Mendez-Vigo, Mayaguez.]

A staff officer, who had been sent ahead to select camp, reported at this time the ground west of the Cabo Rojo road as suitable for this purpose; but owing to the suspected proximity of the enemy, whose position had not yet been determined, it was decided to push ahead and beyond the iron bridge.  This, despite the fact that the men had now marched 13 miles and were very tired.  Once in possession of the bridge and the high ground to the north of it, the command would occupy a strong position, which would make it hard to check its advance on Mayaguez.  Accordingly, the advance-guard, under Captain Hoyt, moved forward, deploying its advance party as skirmishers and its supports into a line of squads.  In this formation it continued until it had approached the bridge within about 400 yards.  At this juncture the enemy opened fire, at first individual fire.  The firing aimed at the advance-guard accelerated the march of the Eleventh Infantry, which ... reported to the brigade commander, whose staff had already commenced the demolition of the wire fences enclosing the road.  About the time that the brigade commander caused the deployment of two companies to re-enforce the advance-guard,—­Major Gilbraith in command,—­the enemy, from his position in the hills to the right front, fired volleys at the main body through the interval separating the infantry advance-guard from the cavalry, wounding a number of men, also an officer and several horses of the brigade staff.  Meanwhile the artillery battalion, under the authority of the brigade commander, had taken up a position to the left of the road.  As the powder used by the enemy was absolutely smokeless, and his position being, moreover, for the most part screened by the trees along the Rio Grande, the question of the exact direction to be given Major Gilbraith’s detachment, and to the lines of battle about to be formed from the main column, became a most perplexing