Very often these columns must contain infantry soldiers, as the demands upon the cavalry were excessive.

Such bodies, moving through a hilly country with which they were unfamiliar, were always liable to be surrounded by a mobile enemy.

Once surrounded the length of their resistance was limited by three things: their cartridges, their water, and their food.

When they had all three, as at Wepener or Mafeking, they could hold out indefinitely.

When one or other was wanting, as at Reddersberg or Nicholson's Nek, their position was impossible.