MACHINE FOR RAISING COALS OR ORE. . 117 



From the uniformity and safety of the new method, their These wearing 

 prejudices against chains are, however, rapidly wearing away, 

 and I have no doubt, that in a few years they will even be 

 preferred. It is certainly more reasonable to suppose, that ' 

 this will be the case, from the superiority which iron holds 

 in point of strength of materials, than that ropes even should 

 have been known, (at least in the mines,) had the new me- 

 thod of working chains been in use prior to the introduction 

 of hemp. 



Reference to the Engraving of Mr. Gilbert Gilpin's im- 

 proved Machine for raising Coal, Ore, &c. PI. 3, fig, 1, 

 2, 3, 4. 



Fig. 1. a. A crank to which the connecting rod is fixed Explanation of 

 to attach the machine to the steam-engine which works it. 'he plate, 



b. A wheel of 13 teeth, wedged about the same shaft with 

 the crank, and which works into the wheel d. 



c. A fly wheel 11 feet in diameter, wedged upon the same 

 shaft as the wheel b. 



(df A wheel of 64 teetii, wedged upon the same shaft as 

 the barrel, into which the wheel b works. 



e. A wooden barrel, formed of two frustums of cones 

 united base to base, and folded spirally with wrought iron 

 tire, which keeps the links of the chains at right angles with 

 each other, and with the grooves in the pulleys. 



ff. The reeling-post and its lever, for disengaging the bar- 

 rel from the steam-engine, when the men are to be let 

 down into the pit by means of the break. 



gg. A break wheel, break and lever, for regulating the 

 velocity of the ban-el when disengaged from the steam en= 

 gine, and in the act of lowering the miners into the pit. 



hh. The frame on which the machine is erected. 



ii. Fig. 2. The pit-frame, for supporting the pulleys. 



k. The pit represented by a circle, part of which is shown 

 open, and part by dotted lines. 



//. Two grooved pulleys, over which the chains, extend- 

 ing a considerable length from the barrel a work in parallel 

 lines. 



m. The carriage (called a tacking in Shropshire) on which 



th« 



