Sound the bugle calls. According to Hardee’s Tactics, used extensively to instruct infantrymen in the Civil War, every officer "should, by practice, be enabled, if necessary," to perform the important function of sounding bugle calls. According to section 55 under "Instruction of the Battalion" in Hardee’s Rifle and Light Infantry Tactics (1862, J.O. Kane edition), "Every officer will make himself perfectly acquainted with the bugle signals; and should, by practice, be enabled, if necessary, to sound them. This knowledge, so necessary in general instruction, becomes of vital importance on actual service in the field." Lieutenant Colonel William J. Hardee published this admonition for career officers of the U.S. Army in 1861. That very year, the Civil War erupted, and huge numbers of civilians were hastily made officers. As Hardee (who ultimately became a Confederate lieutenant general) would have admitted, most of these volunteer officers knew very few of the dozens of bugle calls, and could not sound any of them.