Siege life for the Confederate soldier was a hazardous ordeal; nearly 3,500 were killed or wounded. Because of the limited number of effective troops available to Pemberton, almost the entire Vicksburg Army had to be placed in the trenches; sufficient numbers were not available to rotate frontline duty as was done by the Federal Army. Never knowing when an attempt might be made to assault the defense line, it was necessary for them to be on guard at all times, enduring sun, rain, mud, poor and inadequate food, as well as the bullets and shells of the Union Army for 47 days and nights. The unending barrage of small arms and artillery fire, one Confederate exclaimed, “can be compared to men clearing land—the report of musketry is like the chopping of axes and that of the cannon like the felling of trees.” Rations were generally prepared by details of soldiers behind the lines and carried to the troops at the breastworks. Coffee, the soldier’s staple, was soon unobtainable and an ersatz beverage introduced, the somewhat questionable ingredients of which included sweet potatoes, blackberry leaves, and sassafras. To replace the exhausted flour supply, a substitute was devised from ground peas and cornmeal. When this was baked over a fire, one soldier complained, “it made a nauseous composition, as the corn-meal cooked in half the time the peas-meal did, so this stuff was half raw.... It had the properties of india-rubber and was worse than leather to digest.” Its effect on the digestive systems of the Confederate soldiers was possibly the equivalent of a secret Yankee weapon. A more famous, although not necessarily a more palatable, item of the besieged soldiers’ diet was the mule meat introduced late in the siege. General Pemberton heartily approved of its appearance, observing that mule proved “not only nutritious, but very palatable, in every way preferable to poor beef.” [Illustration: _Bombproofs of the 45th Illinois in Union siege line. Shirley House in background is only surviving wartime building in the park._ From _Photographic History of the Civil War_.] For protection against artillery fire, the Confederate troops dug bombproofs in the reverse slope of their fortified ridge. From these dugouts, bulwarked by heavy timbers, trenches connected with the fortifications, affording the besieged some degree of relaxation in reading or playing cards a few yards from the front line. To defend against surprise night attacks, they were forced to sleep on their arms in the trenches.