CHATTANOOGA, TENN. September 28, 1863.

Brigadier-General GARFIELD,

Chief of Staff, Hdqrs. Department of the Cumberland:

GENERAL: I would respectfully request from department headquarters a letter of advice defining the exact relations which exist between General Morton, chief engineer of this department and myself the chief topographical engineer.

Of late on several occasions there has been some clashing in regard to mutual authority and jurisdiction, which can easily be prevented if our relative positions are officially defined. To make matters clear I will begin at the time when the Corps of Topographical Engineers was merged in the Corps of Engineers, and all branches of the engineering service were placed under one head. This occurred officially on the 3rd of March of the present year. Previous to that time, and, in fact, subsequent to it, the topographical department of this army was a distinct branch and not under the control of the chief engineer. Captain Michler, the former chief topographical engineer, was relieved from duty in this department by Special Field Orders, No. 146, May 29, 1863, and I was ordered to take "his books, papers, orders, instructions, and all public property in his possession."

It will be seen this that as Captain Michler had remained independent of General Morton until he was relieved, and as I had no other orders or instructions than those under which he was acting, that as far as this order was concerned, I was still independent of the chief engineer. In view of the two corps having been united and of the fact that I was and always had been an officer of engineers, and had been acting under General Morton as an engineer officer, I considered the order of the 29th of May as insufficient, and accordingly I wrote and caused to be issued the order of May 31, 1863, known as General Orders, Numbers 124, in which I was announced "as engineer officer in charge of the topographical department, reporting to Brigadier General J. St. C. Morton, chief engineer of the department."

Some little difficulty arose at once in regard to General Morton's jurisdiction over the topographical engineers of the corps, divisions, and brigades of this army from the fact that he had ordered them to report to him. This was settled by General Morton ordering them to report to me. Some conversation arose at headquarters between yourself, the general commanding, and myself, in which it was settled that I was to have sole control and responsibility in regard to all topographical duty, but that General Morton could give me general topographical duty, but that General Morton could give me general orders and instructions. I alone was to have control of the corps, division, and brigade topographical engineers, and no interference was to be permitted between me and any subordinate of mine. All orders to them were to come through me. With this distinct understanding, which I regret to say was never put in writing, such a precaution having been deemed unnecessary, I took charge of the topographical office. I found the headquarters office almost destitute of assistants or means of doing work, and the engineers of the different commands utterly ignorant of what they were wanted for, and equally unstapled with means of doing anything. With great difficulty I have succeeded in establishing an efficient and energetic office at headquarters, and have instructed and equipped the engineers in the field so that they now render good service to