The rain prevented the burning of the bridges and now slowly and surely the pursuing engine began to gain. The raiders tried every way to block the track. At one point they spied a spare rail near a sharp curve. Stopping the engine they fitted it into the track in such a way that it seemed certain to derail the Confederate engine. The latter came thundering on at full speed, struck the hidden rail, and leaped at least six inches from the rail, but came down safely and went whirling along as if nothing had happened. Not once in a hundred times could an engine have kept the track after such a collision. This was the time. Now they were too close to the General to allow of any more stoppages even for wood and water. Andrews decided to risk everything on one last stroke. A mile or so ahead was a wooden-covered bridge. At his orders out of the last car his men swarmed into the engine filling every inch of space, even the tender and the cow-catcher being covered with men. All of the fuel left was piled into the one remaining car, smeared with oil and set afire. Both the doors were opened and the draught as it was whirled along soon fanned the fire into furious flames. They dashed into the dark of the covered bridge with the car spurting flame from both sides. Right in the middle of the bridge it was uncoupled and left burning fast and furiously. It did not seem possible that any engine could pass through such a barrier. There was just enough pressure left in the boiler to reach the next wood-yard and the Union scouts looked back anxiously at the bridge. In a minute they heard around a far-away curve the whistle which sounded to them like the screech of a demon. The Confederates had dashed into the bridge and pushed the flaming car ahead of them to the next switch. The Union scouts had played their last card. There would be no chance of taking in wood before they were overtaken. One thing only was left. They stopped the engine, sprang out, reversed the locomotive and sent it dashing back to collide with their pursuer and then separated to try to make their way back some three hundred miles through the enemy's country to the Union lines. The Confederates, when they saw the engine coming, reversed their own and kept just ahead of this last attack of the old General until its fires died down and it came to a stop. Mitchel, the Union general, but thirty miles west of Chattanooga, waited in vain for the engine which never came. Chattanooga was saved and the most daring railroad raid in history had failed.