HYDRAULIC MACHINERY, FOR MINES 851 



winding, dressing, or pumping purposes, but it might bo advantageously employed to 

 run a telo dynamic cord across country, so as to give motion to various machines. See 



TURBIKE. 



Water-balance. This apparatus is employed at various quarries in Wales, and at 

 numerous places on the Continent. Its chief use is in lifting stuff vertically, but 

 there are many cases where it is applied to incline hauling. 



An endless chain is passed over a head- wheel ; two wrought-iron boxes are attached 

 to this chain, so that when one is at the top, the other is at the bottom of the shaft. 

 Each water-box is covered by a strong platform, which carries a waggon, and each box 

 is fitted with a valve. A pipe in connection with a cistern or reservoir, laid to the 

 mouth of the shaft, is fitted with two valve-boxes. 



The box being filled with water, overbalances the empty box, and raises it with its 

 waggon of stuff to the top of the shaft. "When the full box has descended to the 

 bottom of the shaft, the valve is opened, and the water discharged into the adit or day 

 level. The boxes run in rope guides, and the discharging valves may be opened by an 

 attendant, or otherwise by striking a stud set for the purpose. Bails are laid so as to 

 run the waggons off and on the platforms. Fig. 1180 is a cross elevation, showing 

 the box and waggon at bottom of the shaft, also the charging-pipe and air-vessel at 

 surface; fig. 1181 a side elevation of the box at surface, charging-pipe, brake- wheel, 

 and lever ;fig. 1182 section of box and discharge-valve ; ;fy. 1183 plan of water-box. 



Water-pressure Engines. The power of these engines is derived from the weight of 

 a column of water acting or pressing directly on rams or pistons. 



To work these engines successfully, air-vessels, momentum-plungers, or other 

 suitable contrivances, should be applied between the cylinder and the pressure- 

 column. 



For mining purposes pressure-engines ought to be of simple construction, all parts 

 readily accessible, and the following suggestions more or less observed : (1) Employ 

 cotton-packing in gland-boxes instead of single or cup leathers for iron rods above 

 3 inches diameter ; (2) if it is designed to work under very high pressures, use brass 

 or brass-cased rams ; (3) work with balanced valves ; (4) in forcing water to an accu- 

 mulator, set the pump-valves higher than the pump, or otherwise let the water 

 gravitate to the bottom clack, so as to fill the ram cases, and prevent the ingress 

 of air. 



Owing to the shock communicated to the pressure pipes, as well as to other parts of 

 the machinery, by the sudden stoppage of a flowing column of water, it is necessary to 

 keep the piston speed very low. Long-stroke engines are also desirable. 



It is exceedingly difficult to discover the original inventor of piston reciprocating 

 water-engines, but machines of this class seem to have been first employed in Ger- 

 many. In 1748 an engineer named Winderschmidt erected a water-pressure engine at 

 the Grube Bestandigkeit, Oberharz. Between 1759 and 1768 six additional engines 

 were set to work at Schemnitz, in Hungary, and in 1767 other engines were placed at 

 the Siegfried mine, near Freiberg, in Saxony. In Austria the first water-pressure 

 machine was probably started about the middle of the last century. In 1765 "West- 

 garth erected an engine at the Caldcleugh mine, Northumberland. Five years after 

 Smeaton placed a water-pressure machine at Temple Newsam, Yorkshire. From 1798 

 to 1804 Trevi thick erected engines at Huel Henry and Huel Druid, Cornwall, and one 

 at the Alport mines, Youlgreave, Derbyshire. About 1835 Fairbairn constructed a 

 water-pressure engine for the same mine. Between 1841 and 1848 Darlington de- 

 signed and added three large pumping-engines, one of which, with a cylinder 50 inches 

 diameter, was made at the Butterly "Works, then under the management of the late Mr. 

 Joseph Glynn. Subsequently Armstrong employed an accumulator and rotary engines 

 atAllenheads. In 1833 Dean, of Hexham, and in 1862 Pattinson, Da vison and Spencer, 

 of the same town, built horizontal and vertical engines for the Leadhills Lead Mines, 

 Lanarkshire. Darlington also designed and erected hydraulic pumping-engines at 

 Lisburne. Cwmystwyth, Tarlargoch, and Minera, in North Wales, between the years 

 1843 and 1856. 



Valves The slide-valve shown on page 863, jig. 1194, maybe applied both to small 

 pumping and winding engines intended to be worked under a heavy water pressure. 

 It is an ordinary D-shaped slide made of 3 parts of tin and 16 copper. The seating 

 or face plate is also made of similar composite metal. The valve face is in some cases 

 attached to the face holder in the following manner : (1) Heat valve face holder, and 

 wash face with a solution of chloride of zinc. (2) Ke-heat valve face holder and valve 

 face hot enough to melt tin. (3) Put melted tin on valve face and face holder, bring 

 the two faces together and solder. 



The balance valve shown in fig. 1184 is in use at the Wildberg mines, Prussia. The 

 water under pressure flows through the opening a, then to the main cylinder through 

 the port b. After having performed its work, it returns through the port b and passes 



3i2 



