"Still I don't understand about the duplicate bridges," persisted Harry.

"Why, old Sherman just plays doublets on the rebels. He leads a king at 'em and then plumps down an ace, and after that the left and right bowers. They burn one bridge and he plumps down a better one instead. They blow up a tunnel and he just hauls it out and sticks a bigger one in its place. Great head, that Sherman. Knows almost as much as old Abe Lincoln himself."

"Do you say that Sherman has extra tunnels, too, to put in whenever one is needed?" asked Harry, with opening eyes.

"O, cert," replied Shorty carelessly. "You seen that big iron buildin' we went into to git on the cars at Louisville? That was really a tunnel, all ready to be shoved out on the road when it was needed. If you hadn't bin so keen on the lookout for guerrillas as we come along you'd 'a' seen pieces o' tunnels layin' all along the road ready for use."

As the train dashed confidently over the newly-completed bridge the boys gazed with intense interest and astonishment at the still smoldering wreckage, which had been dragged out of the way to admit the erection of the new structure. It was one of the wonders of the new, strange life upon which they were entering.

The marvelous impressiveness and beauty of the scenery as they approached Chattanooga fascinated the boys, who had never seen anything more remarkable than the low, rounded hills of Southern Indiana.

The towering mountains, reaching up toward the clouds, or even above them, their summits crowned with castellated rocks looking like impregnable strongholds, the sheer, beetling cliffs, marking where the swift, clear current of the winding Tennessee River had cut its way through the granite walls, all had a deep fascination for them. Then, everywhere were strong intrenchments and frowning forts, guarding the crossings of the river or the passages through the mountains. There were populous villages of log huts, some with canvas roofs, some roofed with clapboards, some with boards purloined from the Quartermaster's stores. These were the Winter quarters of the garrisons of the fortifications. Everywhere men were marching to and fro, and long trains of army wagons struggling through the mud of the valleys and up the steep hillsides.

"My, what lots o' men," gasped Harry Joslyn. "We won't be once among sich a crowd. Wonder if Sergeant Klegg and Corpril Elliott kin keep us from bein' lost?"

"Trust Corpril Elliott," said Gid, returning to his old partisanship of the taller veteran. "He knows his business every time."

"Not any better'n Sergeant Klegg," responded Harry, taking up the gantlet for his favorite. "Long-legged men are very good in their way, but they don't have the brains that shorter men have. Nature don't give no man everything. What she gives to his legs she takes off his head, my dad says."