95i Improved Crane and Flexible Chains. 



Watt, and in the raising of coal and ore from the mines, 

 for which purposes ropes had before been solely used at this 

 manufactory. In all cases it has performed with the utmost 

 safety, uniformity, and flexibility ; so much so that the 

 prejudices of our workmen against chains are entirely done 

 away, and they hoist the heaviest articles with more ease, 

 and as great confidence of safety as they would with the best 

 ropes. 



The same method is applicable, at a trifling expense, to 

 all machines at present worked by ropes, or by chains, in the 

 usual way : and all the common chains now in use may be 

 applied to it with equal facility. 



With a' view of ascertaining the relative flexibility of 

 ropes and chains, I wedged an iron pulley, thirty-one and a 

 half inches in diameter, on the spindle of the pinion of a 

 crane of the following description, viz. 



Barrel, 30 inches diameter j 



Wheel, 64 teeth ; 



Pinion, 8 ditto ; 



Top block, with three pulleys of 12 inches diameter ; 



Bottom block, with 2 ditto, ditto. 

 To the large pulley I attached a small rope, for the pur- 

 pose of suspending the weights in the hoisting of the differr 

 ent loads, and the results were as follow : 



* .\\\ the experiments were tiled with the same grooved pulleys. 



The 



