Water for Drinking. 213
sons, it must be recollected that old paths of men or wild animals only mislead ; they go to dry ponds that were full at the time they were trodden, but have since been abandoned on becoming exhausted.
Other Signs.-Well-water may be sought where the earth is still moist, though arid all around ; or, failing that, where birds and wild animals have lately been scratching, or where gnats hover in swarms.
To find the Spring. -From the number of birds, tracks, and other signs, travellers are often pretty sure that they are near water, but cannot find the spring itself. In this case the party should at once be spread out as skirmishers, and the dogs cheered on.
To probe for Well-water.-It is usual, when no damp earth can be seen, but where the place appears likely to yield wellwater, to force an iron ramrod deep into the soil ; and, if it bring up any grains that are moist, to dig.
Pools of Water.-For many days after there has been rain, water is sure to be found among mountains, however desert may be their appearance; for not only does more wet fall upon them, but the drainage is more perfect ; long after the ravines and stream-beds are quite dry, puddles and cupfuls of water will be found here and there, along their courses, in holes and chinks and under great stones, which together form a sufficiency. A sponge tied to the end of a stick will do good service in lapping these up.
The sandy Beds of Watercourses in arid countries frequently contain pools of stagnant water ; but the places where these pools are to be found are not necessarily those where they have been found in preceding years. The conditions necessary for the existence of a pool are not alone those of the rocky substratum of the river-bed, but, more especially, the stratifications of mud and clay left after each flooding. For instance, an extensive bed of sand, enclosed between two layers of clay, would remain moist, and supply well-water during the dry season ; but a trivial variation in the force and