The Engineer Corps—Their Duties—Corduroying—Trestle Bridges—Slashing—Making of Gabions, etc.—As Pontoniers—Xerxes as an Early Pontonier—His Bridge over the Hellespont Described—Our Earliest Pontoon—Bridges of Canvas Boats; of Wooden Boats—Pontoon Bridge Material Described—Balks, Bays, Chesses, Rack Lashings—Pontoon Train—Pontoon Bridge Building Described—Taking Up a Pontoon Bridge—The ’62 Bridge over the Chickahominy—Over the James—Pontoon Bridge Laying before Fredericksburg—The Stability of such Bridges—Incident—Life of an Engineer 377 CHAPTER XXI. TALKING FLAGS AND TORCHES. Old Glory—Signal Flags—The Signal Corps—Its Use—Its Origin—The Kit—The Talking—The Code—A Signal Party—Sending a Message—Receiving a Message—The Torch—General Corse’s Despatch—Signal Stations—Lookouts before Petersburg—“Which one?”—What Longstreet Said—What a Paper Correspondent Did—Reading the Rebel Signal Code—Signal Station at Poolesville, Md.—The Perils of Signal Men—Death of a Signal Officer—At Little Round Top—Anecdote of Grant 394 LIST OF ILLUSTRATIONS. Page. 1. General Grant reprimanded by a Lieutenant _Frontispiece_ 2. Rending the Flag 15 3. A Bell-and-Everett Campaigner 16 4. Southerners discussing the Situation 17 5. A Lincoln Wide-Awake 20 6. “Nayther av us” 21 7. The Minute Man of ’61 23 8. Sweet Little Men of ’61 27 9. Adjutant Hinks notifying Captain Knott V. Martin 29 10. Captain Martin’s Company on its way to Faneuil Hall 31 11. A Drum 33 12. A Dismounted Cavalryman 34 13. A War Meeting 39 14. A Bugle 42 15. On the Lookout 43 16. Mustering in Recruits 44 17. Readville Barracks (from a photograph) 45 18. Sibley Tents 46 19. A, or Wedge Tents 48 20. Spooning Together 49 21. The Hospital or Wall Tent 50