If the ditch be wide and deep, the prolonge is fixed and the handspike turned over on the flask and secured, the team is halted on the edge, and the piece run by hand close to the limber, which then moves slowly until the piece reaches the bottom of the ditch, when it moves quickly until the piece is out. If the ditch be deep and narrow, it may be necessary to cut down the edges and hold back with the sectional picket-line; should the trail sink into the ground in passing over, it is disengaged with a handspike or by fastening a prolonge to it. In passing shallow ditches, drains, or deep furrows the carriages must cross them obliquely. MOVING OVER MARSHY GROUND. Each carriage moves at a distance of 10 to 12 yards from the one preceding it to avoid having to halt; officers or non-commissioned officers are posted at the worst places to instruct the drivers how to conduct their teams. The horses must pull freely and quicken the gait; if the ground be very miry, it may be necessary to assist with sectional picket-lines, or even to use them alone, the teams crossing separately. CROSSING FORDS AND STREAMS. If the ford be not well known, it must be examined and the dangerous places marked before the carriages attempt to cross. If the water be deep and the current strong, great care is necessary. The men are instructed to keep their eyes fixed on some object on the opposite bank which marks the place of exit; they must not look at the stream, and they move rather against the current, so as to better resist its power. If the ford have a bad bottom and the banks be difficult, the teams are strengthened by adding pairs; an officer or non-commissioned officer is posted at the entrance to regulate the distance between carriages and to instruct the drivers how to proceed; a second officer or non-commissioned officer is posted at the exit to direct the drivers how to leave the ford. The management of the team is the same as in crossing marshy ground; the horses must not be allowed to halt or trot either in passing the ford or leaving it, unless the stream be neither deep nor very rapid; in this case the carriages may be halted to let the horses drink, or at least to give them a mouthful of water. Upon reaching the opposite bank the leading carriages are halted after they have moved far enough forward to leave room for the carriages in rear. If the chests be not water-tight and are at the usual height of two feet and ten inches above the ground, a ford deeper than two feet four inches cannot be crossed without danger of wetting the ammunition. If the chests be water-tight or means have been taken to raise them high enough, a depth of 3⅓ feet may be safely attempted.