The Evening Star. WEDNESDAY, JULY 24, 1872.

Evening Star, Issue 2942, 24 July 1872, Page 2

The Evening Star. WEDNESDAY, JULY 24, 1872.

Amongst the papers presented to both Houses of Parliament since the opening of the session are two on water supply to the goldfields. One of these documents contains answers to certain questions put by circular, by the Minister of Public Works to forty-four mining companies on the Thames goldfield, relative to the best mode of water supply. Only seven replies were sent, but amongst them was one by Mr John Gibbons, mining director of the Una Quartz Company and Gold Mining Company, which contains such apparently valuable suggestions concerning conveyance of water that in the hope they may prove serviceable in Otago we reprint them. Mr Gibbons says they are extracted from an article " Showing the failure and defects of the Victorian water supply scheme, and comparing it with the Californian plan.”

Let us ace how they manage similar pipes in California. A private company of miners have lately carried a pipe across a creel;, similar to .Pack Crock except in depth and width, the Californian gully being upwards of 12,000 feet wide, and, 1,050 feet below the inlet end of the pipe, ahd 000 feet bolow the outlet, the pressure of the water being 385 lbs. to the square inch. The pipes are 30 inches diameter, and as the difference of level i* tween the inlet and outlet is 15 foot, the velocity of the water, and consequently the volume discharged in a given time, is very great. The most remarkable thing in the construction of the Californian pipe is that it is made of malleable iron in sheets bent round, double rivettedin the longitudinal seams, and single rivetted in the circular seams, each length being dipped in boiling asphalte as a protection against rust. From the lightness of these, they arc cheaper than cast iron. This is not a mere experiment on the ‘ trial and error’ principle. They were first used by the Spring Valley Water Company. After ten years’ use the pipes are as good as when first laid down. Tim carriage of the pipes was a matter for serious consideration in a mountain region, and the projectors could not afford to waste any iron. They accordingly used light plates where the pressure was light, and heavy plates only where the pressure was great. No. 14 iron was used for the first 150 feet of pressure ; No. 12 for 275 feet, No. 10 for 350, No, 7 for 425 feet, quarter-inch for 800 feet, live sixteenths for 850 feet, and three-eighths for 900 feet. The equivalent thickness of cast iron for the greatest pressure would have been throe inches, or eight times the thickness of the malleable plates. The pipe was laid in a trench five feet deep, and well covered with earth to protect it from changes of temperature, no failure being anticipated, and none having occurred, ihe way in which the work was done was worthy of the spirit in which it was planned. The Scientific Prew says that ‘ the pipe was made at the'rate of 1,100 feet per day, giving employment to a largo number of men. The punching and shearing was done by machinery expressly desigusd for this pipe, and worked as high as SO tons of iron daily, 87,000 foot of pipe being manufactured and laid in place, and the water run through, in four mouths from the commencement of the enterprise. Mr Gibbons remarks :

It seems hardly credible that the Americans, essentially a wood-working people, who apply wood to hundreds of purposes where others use iron, should see the advantage of

using iron, whilst we, belonging to the largest iron-producing and iron-consuming country in the world, are content to adopt in our public works systems and plans obsolete with them many years ago, and use wood for our tramways and waterworks, at double the cost it would be to them. The advantages apparent to me in the Californian system, as applied to the Thames water supply, arc perfect immunity from the accidents and contingencies before alluded to ; a supply of pure water for the town, for domestic and sanitary purposes and for fire ; a constant and reliable water power suitable for turbines or water engines._ and battery supply ; a considerable saving in distance, as regular gradients would not be requisite ; a a 'saving of the fall lost in the necessary gradient of Humes or races ; a wider choice of route ; capability of extension to higher levels, if required in the future ; and a saving in the cost of construction—besides being an engineering work, if carried out properly, that would be a huge source of revenue to the Government, and a lasting monument of its fostering care and foresight.