On the 5th of August Lieutenant Wagner of the Engineers arrived at Gauley Bridge with instructions from General Rosecrans to superintend the construction of such fortifications as might be proper for a post of three regiments. I had already with me Colonel Whittlesey, Governor Dennison's chief engineer, an old West Point graduate, who had for some years been devoting himself to scientific pursuits, especially to geology. In a few days these were joined by Captain Benham, who was authorized to determine definitely the plans of our defences. I was thus stronger in engineering skill than in any other department of staff assistants, though in truth there was little fortifying to be done beyond what the contour of the ground indicated to the most ordinary comprehension. [Footnote: The cause of this visit of the Engineers is found in a dispatch sent by McClellan to Rosecrans, warning him that Lee and Johnston were both actually in march to crush our forces in West Virginia, and directing that Huttonsville and Gauley Bridge be strongly fortified. Official Records, vol. v. p. 555; _Id_., vol. ii. pt.. 445, 446.] Benham stayed but two or three days, modified Wagner's plans enough to feel that he had made them his own, and then went back to Rosecrans's headquarters, where he was met with an appointment as brigadier-general, and was relieved of staff duty. He was a stout red-faced man, with a blustering air, dictatorial and assuming, an army engineer of twenty-five years' standing. He was no doubt well skilled in the routine of his profession, but broke down when burdened with the responsibility of conducting the movement of troops in the field. Wagner was a recent graduate of the Military Academy, a genial, modest, intelligent young man of great promise. He fell at the siege of Yorktown in the next year. Whittlesey was a veteran whose varied experience in and out of the army had all been turned to good account. He was already growing old, but was indefatigable, pushing about in a rather prim, precise way, advising wisely, criticising dryly but in a kindly spirit, and helping bring every department into better form. I soon lost both him and McElroy, my adjutant-general, for their three months' service was up, and they were made, the one colonel, and the other major of the Twentieth Ohio Regiment, of which my friend General Force was the lieutenant-colonel.