Numbers 13. Report of Captain Charles H. T. Collis, Pennsylvania Infantry, commanding Body Guard, of operations May 24-26.

WILLIAMSPORT, MD., May 28, 1862.

GENERAL: I have the honor to report that on the 24th instant, in obedience to your order, received through Captain Abert, of your staff, I halted my command at Cedar Creek, and made preparation to fire the bridge. Upon consultation with Captain Abert, however, we deemed it inexpedient to fire, inasmuch as the head of the column was then being attacked. So, abandoning the idea, I pushed on after you with all haste.

Arriving at Middletown, I discovered I was effectually cut off from the main body by what I believe to have been the reserve of the enemy-a brigade of four regiments of infantry, a few companies of cavalry, and four pieces of artillery, all formed in or near the town. He observed our approach, and made preparations for an attack upon us. I threw my men quickly as possible behind a stone wall on the east side of the road, running along the south side of the town, and within 150 paces of the enemy's position. Our first reception was a whole volley of musketry from right to left, but, thanks to our little breastwork, I had but one man (Charles Fedalen) injured, and he but slightly. The fire was three times returned by my brave men, whose cool aim, short range, and grand position must have had terrible effect. It at all events held him in check for some ten minutes, when he charged along the whole line at double-quick, intending to outflank me. Perceiving this movement I deemed it advisable to fall back, which was accomplished in wonderfully good order. To the credit of my men be it said that this movement was as orderly as though executed upon the drill ground.

We had fallen back a mile, hotly pursued by cavalry, infantry, and artillery, and losing 3 men killed, when, by an intervention of a generous God, we reached assistance. Captain Hampton, First Pennsylvania Artillery, who I supposed was with you, general, now joined me, and placing his guns in battery afforded my men a half hour's rest.

The enemy now formed his line of battle fully 1 1/2 miles long. Out-numbered and almost surrounded, we fell back to Strasburg, where, taking position on the hill north of Hupp's house, we determined to make a final struggle, in which, thanks to the cool bravery of the men engaged, we were successful, forcing the enemy to retire to their first position at Middletown. Colonel Tompkins, First Vermont Cavalry, with about 500 men, came to our aid at Hupp's house.

Captain Hampton, of the battery, deserves the thanks of all engaged, and of the whole country, for his gallant behavior. His guns were supplied admirably and fired with telling effect.

Still determined to rejoin you, and finding the direct road impracticable, I took the western (dirt) road, which brought me out on the pike within 3 miles of Winchester, Colonel tompkins and the battery in the mean time, being mounted, taking the direct road. Colonel De Forest, with a detachment of Fifth New York Cavalry, and Lieutenant Hamilton, with his supply train, joined us on this road, but about midnight we found ourselves again cut off by the enemy's pickets. Retracing our steps, we took the Romney pike, and traveling 27 additional miles approached Winchester on Sunday morning in time to see you evacuate the town, while the enemy took possession.