The Westport Times AND CHARLESTON ARGUS. In the cause of Truth and Justice we strive. SATURDAY, MARCH 11, 1871.

Westport Times, Volume V, Issue 787, 11 March 1871, Page 2

The Westport Times AND CHARLESTON ARGUS. In the cause of Truth and Justice we strive. SATURDAY, MARCH 11, 1871.

What is stated to be a very valuable contrivance for the purpose of raising river water for ground-sluicing or domestic purposes has been invented by Mr J. T. Thomson, of Otago. A model of the maehine has been exhibited at the Otago Institute, and is described as consisting of a fourbladed screw, placed in a frame, and having a crank attached to the axle, by which a force-pump or other machine can be worked. The screw is opposed to the current, which forces it round with more or less rapidity, according to its strength. Mr Thomson claims for his contrivance superiority over the paddle-wheel contrivance, on the grounds that the great size, cost, and weight of the paddle form of wheel creates a most important objection to its general use for goldmining purposes, while the screw contrivance, instead of requiring to be floated by sufliciently strong barges or punts, can be immersed and attached to a buoy, wire rope, boom, bridge, pier, piles, or other fixtures suitable to the various situations. Another great advantage is that the screw may be made of timber, and is easy hi its construction and repair, while any danger it may be liable to from floods is easily avoided by drawing the screw to the bank till the danger from drift is over. Mr Thomson adds, "the screw may be easily made by a common carpenter and blacksmith—in fact out of an old gin case and a piece of scantling I would engage to make a very effective two horse-power machine. The model will be seen to be made of wood, in the makeshift fashion much in us-e on the diggings, the only portion of it executed by skilled labor being the brass force-pump and india-rubber tubing. The screw (or more properly speaking fan wheel, as the blades in this little example are plain and not to the helical curve) is 15 inches in diameter. The blades are set to an angle of 20 degrees to the disc, and in a two-mile current the revolutions are once per second nearly. The pistons of the pump are worked by a crank, and, being single-acting, propel its contents once per second. The diameter of the cylinder is three-quarters of an inch, and stroke of piston 27-10 th inches. The quantity of water per stroke is therefore 1.1925 cubic inch. A screw, eight feet in diameter, is required to raise one sluice head (95 cubic feet per minute) 70 feet above the level of the river, and an approxi-

mate estimate of the cost of the same would be as follows. The duty required would take a single acting pump 14 inches diameter and 18 inches stroke per second, or double acting, 11 inches diameter and 14 5 inches stroke of same velocity • £ s. d. Pump 65 0 0 Screw 20 0 0 50 fathoms of 4|in. galvanised iron wire ... 45 0 0 150 feet of leather 6 inch hose, at 5s per foot ... 37 10 0 150 feet of cast iron 6 inch pipes, at 4s per foot 30 0 0 Carriage and labor (say) 100 0 0

£297 10 0 Of course the cost would be much modified by position and the relative facilities given by the state of the river, its banks, its rocks, and currents In applying the large machinery, it would be advisable to choose such sites as would afford rock foundations for pump and gearings, so as to avoid the necessity of supporting the same by cable or punt, and in such cases the permanent material (cast iron) might be used solely foi" the piping." As a cheap means of utilising river water for all gold mining purposes, and more especially the beach workings, the value of the above invention can scarcely be over-estimated. Its advantages will also be appreciated as an economical and ready means of supplying towns with water for domestic purposes, and in the event of fire offering an excellent protection to property.