To the practical man there are many indications of water.  These, of course, vary in different countries.  Sometimes it is the herbage, but probably, the best of all is the presence of carnivorous animals and birds.  These are never found far from water.  In Australia the not over-loved wily old crow is a pretty sure indicator of water within reasonable distance—­water may be extracted from the roots of the Mallee (Eucalyptus dumosa and gracilis)—­the Box (Eucalyptus hemiphloia) and the Water Bush (Hakea leucoptera).  To extract it the roots are dug up, cut into lengths of about a foot, and placed upright in a can; the lower ends being a few inches above the bottom.  It is simply astonishing how much wholesome, if at times somewhat astringent, water may thus be obtained in a few hours, particularly at night.

Hakea leucoptera.  “Pins and needles.”—­Maiden, in his work “Useful Native Plants of Australia,” says:  “In an experiment on a water-yielding Hakea, the first root, about half an inch in diameter and six or eight feet long, yielded quickly, and in large drops about a wine-glass full of really excellent water.”

This valuable, though not particularly ornamental shrub (for it never attains to the dimensions of a tree), is found, to the best of my belief, in all parts of Australia, although it is said to be absent from West Australia.  As to this I don’t feel quite sure.  I have seen it “from the centre of the sea” as far west as Streaky Bay, and believe I have seen it further West still.  Considering the great similarity of much of the flora of South Africa to that of Australia, it is probable that some species of the water-bearing Hakea might be found there.  It can readily be recognised by its acicular, needle-like leaves, and more particularly by its peculiarly shaped seed vessel, which resembles the pattern on an old-fashioned Indian shawl.

If the water found is too impure for drinking purposes and the trouble arises from visible animalculae only, straining through a pocket-handkerchief is better than nothing; the carbon filter is better still; but nothing is so effective as boiling.  A carbon filter is a tube with a wad of compressed carbon inserted, through which the water is sucked, but as a rule clay-coloured water is comparatively innocuous, but beware of the bright, limpid water of long stagnant rock water-holes.

TO MAKE AN EFFECTIVE FILTER

Take a nail-can, keg, cask, or any other vessel, or even an ordinary wooden case (well tarred inside, if possible, to make it water-tight).  Make a hole or several holes in the bottom, and set it over a tank or bucket.  Into the bottom of the filter put (1) a few inches of washed broken stone; (2) about four inches of charcoal; (3) say three inches of clean coarse sand (if not to hand you can manufacture it by crushing quartz with your pestle and mortar), and (4) alternate layers of charcoal and sand until the vessel is half filled.  Fill the top half with water, and renew from time to time, and you have a filter which is as effective as the best London made article. But it is better to boil your water whether you filter afterwards or not.