SAINT LOUIS, MO., January 3, 1865.

POST ADJUTANT,

Post of Saint Louis, First Sub-District, Saint Louis:

SIR: In accordance with Special Orders, Numbers 23, issued in compliance with circular orders from department headquarters, "to aid in selecting the positions and planning the defenses of the works necessary to secure the military posts, railroad stations, and bridges where troops are stationed in this sub-district," I proceeded to visit the several stations and bridges on the Pacific Railroad from Saint Louis to Hermann, and Southwest Branch as far west as the Meramec Bridge Numbers 2, Moselle Station. Between Saint Louis and Franklin, a distance of thirty-seven miles, the bridges, station-houses, and water-tanks are all standing, as Price did not extend his raid east of that place. At all the principal bridges to that place there are good and substantial block-houses, which were built by Government for the purpose of protecting these bridges. These are no troops at any of these stations at the present time, they having been withdrawn some time since. Between Franklin and Herman, on the main branch of the road, there are five bridges, viz: Saint John's, 180 feet span; Boeuf, 160 feet span, with approaches of 35 feet span, Big Berger, 120 feet span; Little Berger, 90 feet span; Hermann, 110 feet span. These bridges were all burned with the exception of the Saint John's bridge. The station houses, block-houses, and water-tanks were also destroyed. At Herman the bridge has been replaced by an excellent new Howe bridge. The water-tank has been rebuilt. The other bridges have been temporarily replaced by trestle-bridges. There are no troops at any of these stations, nor are there any block-houses or stockades for the protection of these structures. On the Southwest Branch road from Franklin to Moselle Station, the last bridge within the limits of this sub-district, there are five bridges, viz, Brush Creek, 110 feet span; Meramec, Numbers 1, four spans of 110, 140, 165, and 110 feet, respectively; Calvy Creek, 110 feet span; trestle-work, 560 feet in length, and Meramec, Numbers 2, of three spans of 110, 165, and 110 feet, respectively. These were all burned with the exception of the trestle-work and the bridge at Calvy Creek. They have been by trestle bridges which can be but temporarily [used]. The two bridges across the Meramec will probably be swept away by high water the coming spring. At the Meramec bridge Numbers 1 there is a log stockade and several log cabins. These are occupied by a corporal and nine men of the Seventh Kansas Cavalry. The bridge is guarded by them at night, and in the daytime by a watchman employed by the railroad company. At the Meramec Numbers 2 there is a corporal and nine men of the Seventh Kansas Cavalry. They have a good stockade and log cabins fro quarters for themselves and horses. These twenty men I find to be all that are employed in guarding the railroad property at the present time. If it is designed to protect all these bridges by troops it will be necessary to cause suitable block-houses to be erected at most of them, and as there are no troops at them at present, I respectfully ask for further instruction before incurring any further expense.

All of which is respectfully submitted.

H. B. WILSON,

Captain, Sixth Minnesota Infantry.