WATER SUPPLY.

New Zealand Herald, Volume XXV, Issue 8988, 28 February 1888, Page 3

WATER SUPPLY.

Sir, —The importance of water to a community, and " the great and religious interest felt in its supply," may furnish an excuse for reverting to this subject. The progress of sanitary science has led to much greater attention being paid to the adequate supply of water ; and the result of all experience and inquiry has been to bring out more strongly the decided effects on the health of a community arising from the quantity and quality of the water at their command. One cannot help contrasting the local "springs" and water butts in which we put our trust with the magnificent hydraulic works undertaken elsewhere, and by ancient and pagan nations, to provide abundance of water for domestic use and for irrigation. Great works of this kind have existed in Mexico, Ceylon, Assyria, and Egypt from remote antiquity. The " pools of Solomon " were constructed some three thousand years ago to supply the Holy City and its gardens with water from springs ten miles distant. The smallest of these grand water' tanks, which are cut out of the solid rock and finished with massive masonry and cement, would float a good-sized man-of-war. The largest surpasses, in all its dimensions, our new dock just completed at so great an expense. Almost the only work that remains to this day of Carthage is the splendid arched reservoirs formerly used to store the water for the city, which was conveyed by an aqueduct a distance of 60 miles. But even these hydraulic works were far surpassed by those of Ancient Rome. The aqueducts of the Romans were amongst their most magnificent works. Of the nine employed to pour water into their baths and fountains, three are still in use, and give some conception of the vast scale I on which the ancient city must have been provided with one of the most important appliances of civilization and refinement. The water supply of Glasgow from Loch Katrine, and that of New York from the Croton River, are perhaps the most remarkable of modern works to furnish large cities with water. For what may be called a colonial town, Salt Lake City shows the passing stranger what can be done in the way of making brooks of pellucid water to flow along the streets of that healthy and beautiful town. One can admire so pleasing a love of laughing water" even in Utah.

The quality of the supply is of equal importance with the quantity. Impurities exist in water which chemical analysis may not detect. Wells reputed to possess therapeutic properties are often charged with such gases as nitrogen, carbonic acid, carburetted and sulphuretted hydrogen, arising perhaps from the presence in the water of soda, lime, or magnesia. The quantities may be very minute. The strongest Harrogate water, for example, is said to contain only one part of one of these gases by weight to 10,000 of water. Many mineral springs contain Glauber's salt (sulphate of soda) and Epsom salt (sulphate of magnesia). Possibly Lake Takapuna derives its water from the adjoining sea by percolation. In that case the water might- in this way retain a trace of these salts. Any living vegetation, such as reeds or other aquatic plants, would nob materially injure the water, as these absorb carbonic acid and give out oxygen. If the statements made by a correspondent of the Herald are correct, they oply tend to confirm the impression that the Lake water is not of the best quality for drinking, except perhaps medicinally. "As physic has found out by colour, taste, and smell, Which taught the world at first the wonders of the well." With regard to the wonderful natural filter through which the waters of the Lake pass on their way to the sea, all that needs be said is that the resulting fluid is water of the greatest purity. Water will part with organic and mineral impurities by merely flowing for some distance in an open channel. It deposits these by subsidence or by attraction of cohesion, at the same time absorbing air and oxygen from the atmosphere. This can be further accomplished by means of an open reservoir. Providence has the future in view: wo too often can see only the present. It is no idle "dream" to forecast the time when a large population will crowd all these shores of sea and lake. New " marine suburbs" will spring up by the pleasant shores of the ocean, and the amenities of the Lake will be public property. Pure water is an indispensable necessity of life. So also is pure air. The one we must have broughb to our door ; the other we must have means of going to enjoy, Providence having pub both within, our reach. It is not what we pay to obtain either or both that cost us too much, but our neglect of them.—l am, &c., . PUPOKE.