[ 254 ] 

 only as an explanation, which may glvd 

 you a better idea of the manner in which 

 the coals are drawn, than a mere defcrip- 

 tion in words. 



a. Is the canal arched over. 



b. A little branch of it, or rather a 



trough, into which the water is let 

 at pleafure by drawing up the Hiding 

 door c, 



d. A water wheel, into the cavities of 



which the water falls out of the 

 trough b, 



e. A wooden cylinder, to which the 



ropes are faftened j turned by the 

 above water wheel, which winds the 

 ropes round it. 

 ff. The ropes which are faftened at top 

 to the crane. 

 0-. The channel through which the 

 water that turns the wheel, runs off, 

 marked F in the large plan. 

 Each boat contains twelve boxes; two 

 men and a boy are employed in the unload- 

 ing, who arc from twenty to forty-five mi- 

 nutes about each boat load ; this variation is 

 occafioned by caufes which will be explain- 

 ed hereafter. When drawn up, the boxes 



are 



