the bureau of all information for the commanding general, this detachment has been enabled to render itself eminently useful, and to illustrate what the Signal Corps can accomplish when its legitimate duties are intrusted to it.

Major F. W. Marston has been in command of this detachment since August 5, and has displayed the requisite energy and ability for so important a trust. (Appendix C, papers V, F, E.)*

Casualties: One enlisted man killed and 1 died of disease.

Department of the Ohio.-The detachment serving in this department has been small, and has worked under great disadvantages. Many times it has been on foot, with little or no transportation; yet under all circumstances it has preserved its esprit de corps and done valuable service.

May 1 Captain W. G. McCreary, chief signal officer, reported to Major-General Schofield at Charleston, Tenn. He immediately took steps to co-operate with the detachments of the Tennessee and the Cumberland. The army being almost constantly on the move during this month, the principal duties were those of observation and reading and reporting rebel signals.

In the early part of June a station of observation was established on Stoneman's Hill, the highest accessible point, from which the rebel signal station on Lost Mountain was watched and its messages deciphered and referred to the commanding general. When Pine Mountain fell into our possession communication was opened with Major General Sherman. No sooner had our cavalry driven the enemy from Lost Mountain than it was occupied as a signal station. The value of Lost Mountain as a signal station consisted in its being in direct communication with the various headquarters. All communication from one to another had to be sent by that line. No direct communication could be opened from one station to another; hence messages were sent from Geneal Schofield to Lost Mountain, thence to Pine Mountain, and from thence to General Sherman; a distance of about twenty miles by the line and about ten miles by air line. Communications of forty words in cipher code were sent over the line and answers returned in thirty minutes.

During the month of June Sergt. A. G. Blood was wounded and Private E. F. Marshal died.

Captain McCreary reports the officers and men as being faithful and attentive to their duties (Appendix C, papers R, S.)+

Casualties: One officer wounded, 1 enlisted and wounded, and 3 died of disease.

Army of the Potomac.-The following was the organization of this detachment: On the 4th of May, when our army crossed the Rapidan, four officers with the Second, two with the Fifth, and two with the Sixth Army Corps, and one with each cavalry division, leaving twelve with the reserve detachment. Attached to the reserve party were twenty-five men equipped as pioneers, whose duty it was to construct stations. In addition, accompanying each officer and detachment, were the enlisted men used as flagmen, lookouts, &c.

Two circumstances prevented this detachment from being as efficient as it otherwise would have been. First. The army operated constantly as a unit, and he field telegraph, formerly in possession

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*See reports of Marston and Camp, Series I, Vol. XXXIX, Part I, pp. 415, 420. Paper V is journal of A. J. Myer, May 11 to June 23, 1864, here omitted.

+See reports of McCreary, Series I, Vol. XXXVIII, Part II, pp. 538, 539.

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