The Te Aroha Battery.

Thames Star, Volume XIV, Issue 4413, 24 February 1883, Page 2 (Supplement)

The Te Aroha Battery.

The correspondent of the Herald, in a notice of Te Aroha, gives a description of the Te Aroha battery, from which we take the following:-—" This battery, erected through the spirited enterprise of Messrs J. C. Firth and J. M. Clark, is perhaps the most complete mill of its kind in the colony, certainly in the North Island. Removed trom the Waio-Karaka Flat, it has been re«erected at Waiorongomai, and no expense spared to make it as complete as possible. Below the stamper boxes concrete has been laid several feet deep, making a firm and solid bed upon which to. place the stampers. These are forty in number, and are of greajfc weight. One set of stampers has been supplied with silvered plates, instead of the ordinary copper ones. These plates extend for a distance of twelve feet, dispensing with a considerable amount of blanketing, and it is fully expected a much larger per centage of gold will be saved through this means. Another and no less important alteration will be in the gratings. These will be pierced to the number of 1400 to the inch, and when ifc is remembered that those commonly in use at the Thames are under 200, it will readily be perceived how much finer the quartz must be crushed before it will pass through the former. From this fact we apprehend that the charge for crashing .will be relatively higher. The quartz will be supplied direct to the stampers from the large hopper outside the battery building by means of a ■elfrfeeding apparatus fitted to each set,

all of which will be provided with a stone breaker to reduce the quartz to a size suitable for the stamper boxes. The quartz will be driven by means of two turbines, set at either end of the driving shaft, each capable of driving the 40 head alone. The battery is also supplied with twelve berdans for grinding the blanketings. These stand upon a solid concrete floor, and will be driven by a smaller tur» bine set at such a height that the exhaust water from it will supply the battery tables. The hoppers will have a capacity of over 500 tons of quartz, and over 50,000 feet of solid heart of kauri timber will be used in their construction.

The motive power is obtained by means of two races, one of which taps the Waiorongomai, and the other a branch of the Wairakau creek. The combined length of these two races is over two miles, and their construction has entailed no small amuuni of .engineering skill. No less than nine long tunnels were pierced, one of which, on the A or Waiorongonii race was alone 600 feet in length, and was driven from both ends simultaneously. Notwithstanding that the country cut through was of a very rough character, so well were the levels tukea that the drives met almost in a direct line with each other. Besides the tunnels there are eleven flumes, having a total length ef 32 chains. Several of these are carried over deep jjorges, which required very carefully tresselling, and reflect the greatest credit on the contractors. The races terminate at a poiat which gives a fall of 225 i'eet to the battery, and when .the water is turned on there will bs a pressure of 90 lbs. to the inch." :