General McClellan goes more into detail than does the President. He is considering the situation on more technical lines. Yet he does not go beyond the limits of strategy in outlining the general plan. He still conforms to the principles of letters of instruction. If we were to follow General Butler in his journey to the Gulf, we should perceive in his orders the disappearance of the strategic and the appearance of the tactical idea. Later we should discover one of his brigade commanders actually issuing a field order.
Notice in the last example how, on account of its length, General McClellan has made a neat summary of the whole. Notice that in all of these letters the writers have adhered to the principles of rhetoric; and that they have given to the recipient a unified and coherent production. Why? Because the will of the commander is transmitted more quickly in that way.
We have now completed the consideration of the expression which directly affects troops in the field. We have written the field message which brings information to commanders and which helps them to make an estimate of a situation. We have framed the field order which grows out of that estimate and which transforms the decision into action. We have viewed the operation order which is no more than a field order made to fit trench warfare. We have seen orders which are issued in connection with combat so as to govern the movement of trains. We have read letters of instruction which are written by higher commanders in order to regulate in a general way extensive movements. All of these communications bear specifically upon the effort of troops toward success in battle—the ultimate object of all military training.
In leaving this most important part of our professional work, we might take with us this one idea. We can best express ourselves in any of the communications we have studied by having all the thoughts of one kind together and the different kinds in an orderly arrangement. Whenever it is possible we should keep the paragraph sequence,
(a) Enemy.
(b) Own troops.
(c) Plan.
CHAPTER XI
THE WAR DIARY—THE REPORT—ROUTINE ORDERS
We have heretofore considered those communications which aid combat. We now take up those which have no direct bearing upon the outcome of an engagement. We have seen how the field message makes possible by its fresh information the plan for battle, how the field and operation orders frame that plan for battle, how the order maneuvers the trains in connection with battle, and how letters of instruction issue general directions for a campaign of many battles. We now come to the place where the maneuver, enterprise, or undertaking is over. For a variety of future benefits we must have a record of those occurrences. The War Diary and The Report are the communications which perform that office.
THE WAR DIARY
Just as certain individuals keep journals of their lives, so the higher military units keep diaries of their existences. “The War Diary is a record of events kept in campaign by each battalion and higher organization and by each ammunition, supply, engineer, and sanitary train. Entries are made daily and should form a concise history of the military operations. A day comprises 24 hours covered