Spinifex and Sand. David Carnegie
At this point it may not be amiss to give a short description of these peculiar outcrops of granite, without which the track from York to Coolgardie could never have been kept open, nor the place discovered, nor could its early inhabitants have supported life before the condensing plant came into general use.
The interior of the Colony, between the coast and a point some hundred miles east of Coolgardie, is traversed by parallel belts of granite, running in a general direction of north-north-west and south-south-east. This granite crops out above the surface, at intervals of from ten to twenty or thirty miles, sometimes in the form of an isolated barren rock, and sometimes as low ranges and hills several miles in extent. From them small creeks, and sometimes larger watercourses, run down, to find their way into the stony and gravelly debris which usually surrounds the rocks. Much of what little rain does fall is absorbed by the trees and scrub, and much is taken by the sun's heat, so that a very small proportion can sink below the surface soil, and only when there is some underground basin in the rock beneath will water be found by sinking, except immediately after rain.
Round the granite base a belt of grass of no great extent may be found, for the most part dry and yellow, but in places green and fresh. It is in such spots as these that one may hope to tap an underground reservoir in the rock. To these shallow wells has been given the name of "Soaks." They seldom exceed fifteen feet in depth, though similar subterranean basins have been tapped by a well perhaps a hundred feet deep, sunk some distance from the foot of the outcrop. A good soak will stand a heavy drain for perhaps months, but not having its origin in a spring the supply ultimately ceases.
The soil, being alluvial, is in most cases easy to dig, and when the bed rock is reached it becomes an open question whether to go deeper into the decomposed rock or to be content with what supply has been struck. Many a good soak has been ruined by a too ambitious worker, who, after infinite toil, may see his priceless fluid disappear down some hidden crack beneath. Native soaks dug out with sticks and wooden "coolimans"—small troughs used as spades or as a means of carrying seeds, water, or game—are by no means uncommon, and, when holding water, are easily made more serviceable by throwing out a few shovelsful of sticks, stones, and sand, with which they are generally choked. Often the weary traveller has no such lucky help, and must set to work to dig a soak for himself and his thirsty beasts—against time, too, in a blazing sun, without the comforting knowledge that there is any certainty of finding water. I do not know of any case when a party has actually perished at the mouth of a waterless soak, but in many instances water has been struck when all hope had been given up. The skeletons and carcasses of camels and horses tell a tale of suffering that no man who has travelled can look at unmoved, and go to show that many a beast of burden has been less fortunate than his masters.
With what eager anxiety the shovelsful are watched, when the expected "bottom" is nearly reached, by man and beast alike, who, utterly weary and absolutely parched, know that they are soon to learn their fate. The horses snort and plunge in eager and impatient expectation, whilst the patient camel contents himself with grunts and moans, though, as his knees are probably strapped beneath him, he cannot protest more forcibly. At length, perhaps, all are rewarded by the welcome sight of a tiny trickle in one corner, or perhaps the hole turns out a "duffer," and the weary, weary work must be commenced again in a fresh spot.
In many cases these granite rocks have been utilised as a catchment area for tanks, into which the water is led by drains, which encircle the foot of the outcrop. Before the railway was built, such tanks, sunk by Government along the Southern Cross-Coolgardie track, enabled teamsters to bring their horses through with safety, which would otherwise have been impossible at some seasons of the year.
I append a table showing cost and contents of Government tanks excavated at the base of granite rocks between Southern Cross and Coolgardie:—
| Name of Reservoir. | Cost | Contents in Gallons | Cost per Million Gallons (pounds). |
|---|---|---|---|
| Reen's Soak | £3,246 | 900,000 | 3,607 |
| Kararawalgee | 2,947 | 1,250,000 | 2,858 |
| Boorabbin | 3,025 | 900,000 | 3,461 |
| Woolgangee | 3,825 | 1,2501000 | 3,100 |
| Bullabulling | 4,118 | 1,250,000 | 3,294 |
| Coolgardie (No, 1) | 1,167 | 800,000 | 1,454 |
| Coolgardie (No. 2) | 2,110 | 1,400,000 | 1,503 |
| Halgoorlie (half-way) | 1,266 | 500,000 | 2,532 |
| Kalgoorlie … | 1,554 | 500,000 | 3,108 |
| Twenty-five Mile Tank | 1,881 | 500,000 | 3,762 |
| Forty Mile Tank | 1,546 | 500,000 | 3,092 |
| Colreavy's Tank | 2,193 | 997,000 | 2,199 |
The above table will give some idea of the enormous expense entailed by the opening up of the interior. In addition to these, wells and bores were put down, many of which failed to strike water.
Ever-thoughtful Nature has provided, on the surface of the "granites," small reservoirs which, after rain, may, in some cases, hold many hundred gallons of water. The Rock—or Namma-holes (I presume "Namma" is a native name, but of this I am uncertain) are usually more or less conical in shape, and vary in depth from a few inches to twenty feet, and in diameter from half a foot to several. Their sides are smooth, and slope down to a rounded bottom, where stones are often found which would suggest that they have had something to do with the formation of these peculiar holes. Beneath a hard surface layer the rock becomes decomposed and comparatively soft; and doubtless the rain of countless ages collecting round the stones, once on the surface and now found at the bottom of the holes, has at length weathered away the rock, and so by slow degrees the stone has ground out an ever-increasing hollow. I am neither geologist nor dentist, but I have often likened in my mind the formation of the Namma-holes to the gradual hollow formed by decay in a tooth. Whatever their history, their use is unquestionable—not so the flavour of their contents; for every bird or beast coming to water will leave some traces behind, and the natives, to prevent evaporation, throw in sticks, stones, and grass. Such a collection of rubbish and filth might naturally be supposed to render the water unhealthy, but apparently this is not the case, for we have often been forced to drink water, which, in civilisation would be thought only fit to be used as manure for the garden, without any injury to health or digestion. Patient search over the whole surface of the rock is the usual method for finding rock-holes, though sometimes the pads of wallabies, kangaroos, or emus,