THERE is nothing impossible to any army in time of war. Bridges are thrown across rivers in a night; roads are constructed as the line advances; telegraph wires are uncoiled in the wake of the moving regiments. To protect from a delay that might mean defeat, the army frequently carried its own "bridges" with it. These army or pontoon bridges consisted of boats over which planks were thrown to span the waterways. This view shows two of the boat's wheels ready for the march. Each pontoon wagon is drawn by six mules. These pontoons were always getting stuck in the mud, and the soldiers, struggling along under their own burdens, were obliged to haul on the drag ropes, and raise the blockade. Probably no soldier will see this picture without being reminded of the time when he helped to pull these pontoons out of the mud, and comforted himself by _shouting at the mules_. A view is also shown of a pontoon bridge across the James River ready for the approach of the army. It was often necessary to establish an immediate telegraph service between different points in the lines. This photograph shows one of the characteristic field telegraph stations. An old piece of canvas stretched over some rails forms the telegrapher's office, and a "hardtack" box is his telegraph table; but from such a rude station messages were often sent which involved the lives of hundreds and thousands of soldiers. The building of corduroy roads to allow ammunition and provision trains to pass on their journeys was of utmost importance. An hour's delay might throw them into the hands of the enemy. Many disasters were averted by the ingenuity of the engineers' corps. [Illustration: PONTOON BOATS ON WHEELS] [Illustration: BUILDING A CORDUROY ROAD] [Illustration: FIELD TELEGRAPH STATION IN OPERATION] [Illustration: PONTOON BRIDGE ACROSS JAMES RIVER]