34 Of the Under- ground inclined Flmie 



•up and down; and are divided by a brick wall, fu'pportirig 

 the roof, in which arc openings for a perfon to efcape out of 

 the way of the boats ; which double waggon- way joins in 

 one, about fifty- feven yards from the lower level. 



The whole width of the double waggon-way is nineteen 

 feet; and of the fingle waggon- way, after the jun6lion, ten 

 feet. 



Thefe waggon-ways are fupplied with iron rails, or gul- 

 lies, laid on Heepcrs, down the whole run ; and the height of 

 the roof, above the iron rails, is eight feet. 



At the top of the inclined plane there is a double lock, or 

 rather two locks, fide by iide, formed in the heart of the 

 fame rock, which deliver the loaded boats from the higher 

 level down the inclined plane, and receive the empty boats 

 from the lower. The length of that part of the tunnel in 

 which thefe are formed, is eighteen yards; the width or 

 diameter, twenty feet fix inches ; and the height of the roof, 

 at tlie north end and above the locks, at dd^ Plate I. fig. 4. 

 twenty-one feet, to admit the break- wheel. 



The bottom, or fouth end of the inclined plane, is fix feet 

 nine inches under the furface of the water, where the loaded 

 boat floats oflf the carriage upon the canal of the lower 

 level.. 



The depth of the lock?, under water, at the north end, is 

 four feet fix inches ; at the fouth end it is eight feet. 



The wall between the h)cks is nine inches above the fur- 

 face of the level water ; its breadth is three feet. 



The diameter of the horizontal main-lliaft, upon which 

 .the rope works to let the loaded boats down, and to draw the 

 empty boats up, is four feet eleven inches, and its circumfe- 

 rence is fifteen feet five inches. The main-rope is two 

 inches and a half in diameter, and feven inches and a half 

 in circumference. It is lapped round with a fmall cord of 

 about an inch in circumference, for the length of about out 

 . hundred and five yards, to prevent its wearing, which it does 

 chiefly when it drags upon the bottom, when at work, at the 

 place where the waggon-w^ays unite ; and, for the fame 

 purpofe, rollers of eight inches diameter are fixed at intervale 

 liovvn the- run of the inclined plane. Moreover, a hollow 



call- 



