49* Dule of Bridgeivater" s underground inctimd Plant. 



No. 2. A paddle to let the water out of the lock Ay into the pit No. i. 



No. 3. A paddle to let the water out of the lock S, through a culvert, reprefented by 

 dotted lines, under the lock J, into the pit No, t. 



No, 7, 7. Paddles in the lock-gates, to let the water out of the higher level into the 

 locks. 



No. 8, 8. The two north lock-gates, one to each lock, which turn upon the heels of 

 the gates, and fwing round when they are opened or fliut. 



No. 10, 10. Two flops or doughs, one to each lock, which ferve as lock-gates to the 

 fouth end, and are raifed and let down by a windlafs. 



S, A flop, which is ufed occafionally when the lock-gates want repairing. 



T, The place where the boats which are to pafs to or from the lower (ingle waggon-way 

 are diredted, at pleafure, into either part of the double waggon-way, by a moveable iron 

 fleeper or plate at that point, upon which fleeper or plate the wheels of the boat-carriage or 

 cradle run. 



TMe of Reference to Plate XXI. Fig. 4, of his Grace the Duke of Bridgewater's 

 Under-ground Inclined Plane, at Walkden-Afoor Colliery , near Worjley, in Lancajhire . 



1. Main-fliaft, on which the rope laps. 



2. Break-wheel, on one fide of which , the fpur- wheel is faftcned. 



3. Nut-wheel, out of geer, but which Aides into the fpur-wheel, when ufed to draw the 

 empty boat into the lock occafionally, and which is fupported by two uprights from the 

 pillar to the roof. 



4. 4. Winches or handles, to work the nut and fpur-wheel. 



5. 5. The main-ropes faftened to the boats, and which are lapped to prevent their 

 wearing. 



6. The fpur-wheel, which is faftened on one fide of the break-wheel ; and on which 

 break-wheel is a ftrong iron-jointed timber brace, which,- according to the preffure given 

 thereto by the man who attends it, will allow the loaded boat to defcend quick or flow, or 

 detain it in its pafiage. 



7. 7. Paddles in the lock-gates, to let the water out of the higher level into the lock. 



8. A hollow caft-iron roller, to prevent the main-ropes from fwagging. 



9. Shroud-wheel, to prevent the ropes going over the end of the main-fliaft, flipping off, 

 jerking, or breaking. This ftands three inches above the main-fhaft. 



Concerning 



