342

MODERN STEAM PRACTICE.

fronting the dock at the levels of the several floors, and each isprovided at the first floor with a delivery outlet, to which a movablespout is hooked on, for delivering grain from the warehouse intovessels. The arrangement of the lowering band machinery is acounterpart of the upper, but upon a smaller scale, and without themovable throwing-off carriages provided on the upper bands, whichare not required for the lower. These lower bands are employedfor the purpose of conveying grain from any of the descendingspouts to any of the five elevators W, which are fixed in the cranetowers. The grain conveyed along these 12-inch main bands isthrown upon the 18-inch cross bands, which deliver it into thehopper X, supplying the elevator W; one 18-inch cross band willcarry the full quantity of grain conveyed by the two 12-inch bands,and the cross bands are arranged to receive their motion fromeither line of the main bands. Much of the grain discharged fromthe vessels in the dock is sorted upon the quay, and is then thrownby hand into the hopper X of the elevators.

The elevator for raising the grain from the bottom to the top ofthe warehouses is shown on a larger scale in Fig. 217. The wrought-iron bücket w, capable of containing about 21 cwts., is slung fromthe lifting chain by an arrangement of bars and levers, and providedwith guiding rollers running between the upright timbers, soarranged that on reaching the top the bücket tips over, and dis-charges the grain into the hopper Y. This hopper delivers thegrain upon the same inclined cross bands Q that convey it fromthe outer crane hopper P. The bottom hopper is made in twoparts, the upper of which X, protected by a grating, receives thebulk of the grain, while the lower compartment Z contains only oneCharge at a time for the elevator bücket w, and is separated fromthe upper portion by a sliding valve. The descending speed of thebücket having been checked, as it approaches the bottom it strikesthe arm of the tappet lever A, which closes the valve between thetwo compartments X and Z of the hopper; and continuing itsdescent still more slowly, the bücket strikes another tappet arm B,which disengages the iron flap C that covers the front of the lowercompartment Z; this flap, falling forwards by the weight of thegrain behind it, shoots the contents of the lower hopper Z into thebücket W. As soon as the bücket has received its Charge themotion is reversed for lifting. Beginning to ascend at a moderatespeed, the bücket closes the flap C of the lower hopper, which