another abutment and its approaches completes the main part of the work.
It then remains to scatter the roadway of the bridge with a light covering of hay, or straw, or sand, to protect it from wear, and, perhaps, some straightening here and tightening there may be necessary, but the work is now done, and all of the personnel
may cross with perfect safety.
No rapid movements are allowed, however, and man and beast must pass over at a walk.
A guard of the engineers is posted at the abutment, ordering “Route step!”
as the troops strike the bridge, and sentries, at intervals, repeat the caution further along.
By keeping the cadence in crossing, the troops would subject the bridge to a much greater strain, and settle it deeper in the water.
It was shown over and over again that nothing so tried the bridge as a column of infantry.
The current idea is that the artillery and the trains must have given it the severest test which was not the case.
In taking up a bridge, the order adopted was the reverse of that followed in laying it, beginning with the end next the enemy, and carrying the chess and balks back to the other shore by hand.
The work was sometimes accelerated by weighing all anchors, and detaching the bridge from the further abutment, allow it to swing bodily around to the hither shore to be dismantled.
One instance is remembered when this manoeuvre was executed with exceeding despatch.
It was after the army had recrossed the Rappahannock
, following the battle of Chancellorsville
So nervous were the engineers lest the enemy should come upon them at their labors they did not even wait to pull up anchors, but cut every cable and cast loose, glad enough to see their flotilla on the retreat after the army, and more delighted still not to be attacked by the enemy during the operation, -so says one of their number.
One writer on the war speaks of the engineers as grasping “not the musket but the hammer
,” a misleading remark, for not a nail is driven into the bridge at any point,