But very often warfare has to be carried on in the most outlandish places where armies can only travel light, and where, hampered by bridging material of
the conventional sort, they would have no chance in catching up with a fleet and agile native enemy. Yet bridges are needed even more under those conditions perhaps than under any other. There are many examples of this in the wars just beyond the frontier in Northern India. Then ingenuity has to make good the luck of prepared material and the bridges are made of those materials which happen to be procurable.
An army in India once wanted to cross a river, where no materials of the ordinary kind were available. The river, however, was lined with tall reeds. A reed has for centuries been a favourite example of weakness and untrustworthiness, so how can reeds be made to form a safe bridge? This is how it was done.
Great quantities of reeds were cut and were made up into neat round bundles about a foot in diameter. Ropes were scarce too, but these likewise were improvised by twisting long grasses into ropes. It is surprising what good ones can be made in this way, and they served their purpose well. Many bundles having thus been made numbers of them were tied together so as to form rafts. Each bundle in fact was a small pontoon, and the rafts which were thus constituted differed only in size from the regulation rafts made of pontoons.
While this work was being done two ropes were got across the river and secured on both banks: then rafts were floated down in succession, each one on arrival being tied up under the two ropes. Finally a track of boards was laid over the centre and the
bridge was strong enough for men in fours to walk over it.
Had it been necessary, the floor could have been made of brushwood, interlaced so as to form a kind of continuous matting or of a layer of branches covered with canvas. Floors for bridges can be made in many ways.
A dodge which soldiers in the British Army are taught is how to make boats for bridging purposes out of a tarpaulin or piece of canvas, supported on a framework of light wood poles or twigs. The outline of the boat is first drawn roughly on the ground. Then three posts are driven in on the centre line of the boat and to the top of these three a horizontal pole is tied, thin, flexible branches stripped of their bark, being fixed by having their ends stuck in the ground on either side. The ends are driven in on the outline already marked out so that when done the branches form a framework like the ribs of a boat upside down. Other branches are intertwined among these so as to bind them together and finally a tarpaulin or canvas sheet is laid over all. A number of boats formed after this fashion can be used as pontoons to support a bridge, or several can be made into a raft and towed to and fro—a sort of floating bridge.
Another scheme is to make a number of crates like those in which crockery and other things are often packed. These are of very simple and easy construction, consisting of sticks slightly pointed at the ends driven into other pieces which are perforated with suitable holes to receive the ends. The only
tools necessary are an axe (or even a pocket-knife will do) to sharpen the ends and an auger to make the holes. Almost any sort of wood can be made to serve. The cover for this, and indeed for most of these improvised rafts, is tarpaulin or canvas, the latter of which, being the material used for so many purposes, is almost sure to be available in some form or other.