Weir

—A wall or dam acro a stream, over, the top of which the escaping water flows. | Welding Transformer.—An alternating The object of placing a weir may be for, current transformer for reducing a current raising the level or for affording a means ' pre ure and greatly increasing its volume of measuring the quantity which pa es;; for purposes of electric welding. in the first case, the impounded water may | be led to a mill, a sluice or a fish trap; in the: Western Union Wire Joint.—A simple second the mean depth of water flowing over the, weir is carefully gauged. and its speed noted By | method of joining the ends of two wires so _ continuous observations. For measuring sma as to be mechanically strong and preserve streams, a notched board is employed, and under electric conductivity. It consists in over the name of tumbling bay, its use is very common. lapping the ends of the bare wire for a few inches, and then twisting each end around Welded Rail Bond.—A method of joining the other wire for a few turns. The strength of rails in which bolts are dispensed with, the ` this joint unsoldered is from 50 to 55 per cent of ends of two rails being firmly welded to the strength of the wire: when soldered it becomes 80 or 90 per cent of the strength of the gether by an electric welder specially dewire itself. It is also called the American twist signed for the purpose. joint.