Mr. Eckhardt*s Regulator. 83 



vanes or wlno-s, which lave in the water of a circular cistern 

 or well. In justice to a very ingenious man, Mr. William 

 Robert, of the neighbourhood of Swansea, in South Wales, 

 I beg to mention that a regulator on this principle was con- 

 trived by him, and executed in 1793; since which the same 

 has been employed, with the most perfect success, in Messrs. 

 Lockwood and company's collieries, where the coals from 

 the upper veins of the mounlaiii require to be let down in 

 lar^e quantities to the trainway tunnel below, in order to 

 their being conveyed out of the hill to the navigation. It is 

 difficult to conceive any regulator better adapted for harni- 

 Icsslv destroying the immense power generated bv the long 

 and ahnost constant descent of large baskets of coals in these 

 mines; the velocity of the descent being adjustible to the 

 greatest nicety by means of cocks, which let in or out water 

 from the regulator well, as occasion may require : at the 

 same time permit mc to remark, that few situations seem 

 less adapted for this kind of regulator, or rather destroyer 

 of power, than the one in which Mr. Eckhardt has exhi- 

 bited it in the work above quoted, where the expensive and 

 cruelly-excited labour of animals ought to have been more 

 (Economically regulated. A more serious defect attends Mr. 

 Eckhardt's mode of applying the labour of animals, viz. on 

 the outside of a walking-wheel, owing to the increase of 

 power, (instead of its decrease,) whenever the animal abates 

 its muscular exertion, and the wheel is moving, as on all 

 occasions of ceasing work. This will evidently appear from 

 an inspection of the 21st plate as above ; where an ox is re- 

 presented standing with his fore feet upon a stage fixed nearly 

 over, but a little before the to]i of a walking-wheel, while 

 his hind legs rest and act on the wheel at a consideral)le di- 

 stance bevond its top. Whenever the animal's hind legs 

 happen, by the motion of the wheel, to be carried further 

 than usual from his fore legs, how is he to recover himself? 

 Not only will the weight of his hind quarters, acting on an 

 increased radius, accelerate its motion, but his hind leg"?, 

 brought continually nearer into the direction of a tang(;nt lo 

 the wheel, will give his muscular exertion an increasing ef- 

 fect on the wheel as he endeavours to prevent the pro- 

 Y 2 gressivc 



