MECHANICS AND USEFUL ARTS. 67 



cages in which the miners descend into and ascend from the pits. 

 Such accidents not only cause destruction of human life, but in shafts 

 which are fitted up with guides, according to the most improved prac- 

 tice, occasion considerable damage to the shaft-fittings. The object of 

 Mr. Foudrinier's invention is to fix, in all such cases, the corve or cage 

 firmly and instantaneously to the guide, through the instrumentality of 

 self-acting springs, levers, and wedges, attached to the top and form- 

 ing part of the cage. These corne into action when disengaged 

 through the breaking of the rope or chain, that is, in the very in- 

 stant at which the accident occurs. The apparatus is so admirably 

 contrived, that, through the operation of simple mechanical principles, 

 the tightness with which the wedges hold increases in proportion to the 

 increase of weight in the cage. There is in mining operations anoth- 

 er source of danger, in the liability of the load to be drawn up against 

 the pulleys, through the negligence of the engineer, an accident 

 attended with next to certain death to the men, as well as great darn- 

 ao-e to the shaft. The risk attending such an accident Mr. Foudririier 



O "-j 



also obviates, by attaching to the rope or chain a disengaging appara- 

 tus, such as that made use of in the pile-driving machine, the corve 

 being, at the moment of disengagement, left affixed to the guides at a 

 certain distance below the pulleys. In this case, also, the apparatus 

 is self-acting. Mr. Foudrinier is known to have perilled his own safe- 

 ty in order to test the efficiency of his apparatus. At the Usworth 

 colliery, in the county of Durham, where it has been in operation 

 since the 16th of April last, it has more than once been subjected to 

 very severe trials, and a number of colliery viewers and engineers 

 having seen the cage, though loaded with two full tubs, and weighing 

 about 2 tons, stopped instantaneously upon the disengaging of the rope, 

 have come forward to bear public testimony to the value and complete- 

 ness of the invention. The apprehension which some persons had en- 

 tertained with reference to the fall of a portion of the rope, when bro- 

 ken, on the top of the corve or cage, appears to have been removed by 

 a communication from Mr. Elliot, the owner of the Usworth colliery, 

 which was published in the Mining Journal of the 28th of July last. 

 Mr. Elliot there states, that in the Usworth colliery, a broken rope, of 

 about 200 fathoms in length, and weighing about 37cwt, had in that 

 month fallen on a cage top there in use, consisting merely of a 3-inch 

 Memel plank, without any injurious result. This he explained by 

 the circumstance that the fall of the rope is distributed over several 

 seconds of time, and that, consequently, the latter does not acquire 

 the momentum which would be acquired by a mass of the same weight 

 when descending in a compact and solid body. The numerous exper- 

 iments made at Birmingham with this apparatus afforded the highest 

 gratification to many of the distinguished persons who attended the 

 meeting of the British Association ; and Dr. Buckland and many oth- 

 er gentlemen expressed a high opinion of its value. London Times. 



