The line is hauled in by a steam or electric winch, and the sounding-tube containing a sample of the bottom deposit is rapidly brought on board.
The frames hang vertically from the bottom of the overhead bridge, and rest against a sill at the bottom when the weir is in operation, the openings between the frames being closed below the water-level by rolling-up curtains or sliding panels, which are lowered or raised by a travelling winch carried by a small foot-bridge formed by hinged brackets at the p ack of the frames, and situated a little above the highest floodlevel.
Trans., 1788, p. 403) of "an instrument which by turning a winch produced the two states of electricity without friction or communication with the earth."
The other six are connected to each other and to the lowest one by wire cables and pulleys in such a way that when the cable which connects the two lowest tubes is wound in by means of a winch, each of the tubes except the fixed one will rise within the next one through the same distance.
The trestles of this weir are, as usual, hinged to the apron, so that in flood-time they can be completely lowered into a recess across the apron by means of chains actuated by a winch, leaving the channel perfectly open for the discharge of floods and for the passage of vessels when the lock is submerged.
He was probably dead and buried in his chapel at East Winch before November 27, 1308, the date of the patent by which Henry Scrope succeeded him as a commissioner of trailbaston.
This arrangement has been provided at several weirs on the Thames, to afford control of the flood discharge, and reduce the extent of the inundations; the largest of these composite weirs on that river is at the tidal limit at Teddington, where the two central bays, with a total length of 2421 ft., are closed by thirty-five draw-doors sliding between iron frames supporting a foot-bridge, from which the doors are raised by a winch.'