The Gap in Missionary Ridge at Rossville. Through this Georgia mountain-pass runs the road to Ringgold. Rosecrans took advantage of it when he turned Bragg's flank before the battle of Chickamauga; and on November 25, 1863, Thomas ordered Hooker to advance from Lookout Mountain to this point and strike the Confederates on their left flank, while in their front he (Thomas) stood ready to attack. The movement was entirely successful, and in a brilliant battle, begun by Hooker, Bragg's army was swept from Missionary Ridge and pursued in retreat to Georgia. [Illustration: THE SKIRMISH LINE COPYRIGHT, 1911, PATRIOT PUB. CO.] Multiply the number of these men by ten, strike out the tents, and we see vividly how the advancing line of Thomas' Army of the Cumberland appeared to the Confederates as they swept up the slope at Missionary Ridge to win the brilliant victory of November 25th. This view of drilling Federal troops in Chattanooga preserves the exact appearance of the line of battle only a couple of months before the picture was taken. The skirmishers, thrown out in advance of the line, are "firing" from such positions as the character of the ground makes most effective. The main line is waiting for the order to charge. [Illustration: BATTLE OF MOBILE BAY. _Painted by E. Packbauer._ _Copyright, 1901, by Perrien-Keydel Co., Detroit, Mich., U. S. A._] THE BATTLE IN THE WILDERNESS The volunteers who composed the armies of the Potomac and Northern Virginia were real soldiers now, inured to war, and desperate in their determination to do its work without faltering or failure. This fact--this change in the temper and _morale_ of the men on either side--had greatly simplified the tasks set for Grant and Lee to solve. They knew their men. They knew that those men would stand against anything, endure slaughter without flinching, hardship without complaining, and make desperate endeavor without shrinking. The two armies had become what they had not been earlier in the contest, _perfect instruments of war_, that could be relied upon as confidently as the machinist relies upon his engine scheduled to make so many revolutions per minute at a given rate of horse-power, and with the precision of science itself.--_George Cary Eggleston, in "The History of the Confederate War."_