The Viaduct Works' Handbook

97 on the circumference, the radius of which is the length of the hammer arm. The time and cost of fixing and refixing swages, when changing from one class of work to another, is saved.—There are no standards required for the hammer, and the smith is not confined to height or width of forging.—The striker will work at any height up to 6 feet from the floor, and can be raised or lowered in a few seconds. It can also be quickly arranged for striking perfectly level blows upon the plane of the anvil in all positions, and the blows are equally effective in all directions, from vertical to horizontal on either side the centre. It will forge shafts or bolts of any diameter, round and true, without the use of swage. —It will weld plates, bars, angle-iron, ships’ beams, &c., and is very useful in bending and setting angle and T-iron stiffeners foi bridge and girder work.—The hammer head when not at work is raised off the face of the anvil, which enables the smith to place his heat under it at once.—One striker will keep eight fires and a furnace in operation, and take the place of four men, and produce the work at about one-third the price of hand labour. The price of these strikers varies according to the appliances with which they are fitted, from £70 to £180. PATENT SAND PUMP OR EXCAVATOR. The accompanying illustration represents a very useful machine, invented by Mr. Howard Kennard. It was first used in sinking the cylindrical piers of the Tagus bridge, and afterwards at Mondego and other bridges, referred to in the former part of this book; and it has recently been employed with much success in erecting the cy- lindrical piers of the bridges on the Delhi Railway, at the Sutlej bridge the sand pump, in one day of seven working hours, having sunk a pile 12 feet 6 inches in diameter 6 feet, or excavating 736 cubic feet of sand, the pile at the time being about 36 feet in the ground. It also sunk 15 feet in eighteen hours, part of the time working in black clay and kunkur. The pump, as now made, consists essentially of a wrought-iron cylinder, the length of which is somewhat less than its diameter, and its diameter about half that of the pile to be sunk by it. Its top is closed, and at the centre thereof is attached a small cast-iron G