(2) The Eastern Department, with headquarters at Governors Island, New York. (3) The Southeastern Department, with Headquarters at Charleston, South Carolina. (4) The Central Department, with Headquarters at Chicago, Illinois. (5) The Southern Department, with Headquarters at Fort Sam Houston, Texas. (6) The Western Department, with Headquarters at San Francisco, California. (7) The Philippine Department, with Headquarters at Manila. P. I. (8) The Hawaiian Department, with Headquarters at Honolulu, Hawaii. You will be in one of these departments. Address your communication to "The Commanding General" at his department headquarters. Answer all official communications promptly. This is important. Letters must be written, folded, signed as prescribed by the War Department. Models illustrating the system are furnished by the Adjutant General's office, Washington, D. C. "Ind." is the abbreviation for indorsement. (Correspondence Model) COMPANY B, 40TH INFANTRY, Fort William H. Seward, Alaska, July 19, 1916. From: The Commanding Officer, Co. B, 40th Inf. To: The Adjutant General of the Army (Through military channels.) Subject: Philippine campaign badge, Corporal John Doe. Inclosed are lists in duplicate of the enlisted men of Company B, 40th infantry, entitled to the Philippine campaign badge. John A. Brown, Capt., 40th Inf. 1st Ind. Hq. Ft. William H. Seward, Alaska, July 19th, 1916.-- To the Comdg. Gen., Western Department, San Francisco, California. A. F. R., Brig.-Gen., Comdg. 2d Ind. (Incl. is the abbreviation for inclosure.) (Stamp) Rec'd Western Department, July 30, 1916. (Note. This correspondence is not complete but it illustrates how to write a military letter and indorsement.) USE OF THE COMBINED ARMS Every efficient officer must realize the possibilities and limitations of his own arm of the service as well as the possibilities and limitations of the other arms. Each arm of the service is necessary and important. A proper understanding of the use of the combined arms is as essential to success in battle as coöperation between the different members of a football team is to its success. Don't "knock" any arm but the one you are in, and don't knock that unless you are willing to admit you are not man enough to improve it. INFANTRY "The infantry is the principal and most important arm, which is charged with the main work on the field of battle and it usually decides the final issue of the combat." (Field Service Regulations.) The rôle (duty or job) of the infantry, whether offensive or defensive, is the rôle of the entire force. If it fails, all fail. When properly supported by artillery, trained infantrymen armed with rifles, bayonets, and the will to put the enemy out of action, will settle all issues. ARTILLERY