MAN-ENGINE 195 



spars joggled, as in the former cases; but in the two grooves run in these there were let 

 in two iron- wire ropes of 12 wires each. The two spars were screwed tight upon tho 

 ropes, which were steeped in prepared tar. Thus the ropes formed a core to th 

 wooden rods, which in themselves were sufficiently strong for the strain, but the ropes 

 were a protection, should the wood decay, against any misfortune, while the wood 

 gave sufficient stiffness to the rope-rod. These rods wore not above half tho weight 

 of the former per fathom. 



It was very fairly objected to .this construction, that it was uncertain what strain 

 came on the wood, what on the iron, and that damage on the iron wire could not be 

 observed. 124 fathoms of the 265 were provided with a power-ladder of this con- 

 struction. Tho ascent on it is not continuous, but alternating, as in the Duke George 

 William shaft, so that of 143f fathoms, 124 are by the machine, 19| on the fixed 

 ladders. 



These being accomplished, several experiments -were begun in 1836 to endeavour 

 to arrive at a construction of rod, at once lighter and mechanically 'more perfect. 

 First, a wire-rope ladder, as it wore, laid along planks as a continuous bearing, and 

 having here and there rollers, so attached as to keep the rope down on the planks, 

 was tried. Steps and hand-holds were made fast to the rope, so that no injury 

 resulted to the rope. The necessary stiffness was wanting, the small rollers were 

 insufficient, and the planks were very rapidly worn. Second, a wire rod, as it were, 

 of four ropes in a square, nine wires in a rope, with inch boards on one side running 

 on fixed rollers. The four ropes made a parallelogram of 6 and 7 inches, between 

 which hand-holds and steps were fastened. The boards were protected by iron 

 friction-pieces, where they ran on the rollers ; ten fathoms weighed 42'9 Ibs., and 

 cost about one hundred thalers. The only objection to this was, that tho lour ropes 

 could not bo depended upon as being equally strained. Third, Albert's proposal to 

 have two ropes of the wire parallel to each other, 2-inch and 10-inch deals to bo 

 attached to the back of these, without any other connection : to let these run as 

 usual on rollers, and fastening the steps and hand-holds to the ropes. It was tried 

 in Duke George William's shaft, and found the most noiseless and easiest in go, and 

 on the whole, most perfectly fulfilling tho required conditions. This construction, with 

 some modifications by M. Jordan, was finally determined upon, and has since been 

 carried out in the Samson shaft, in Andreasberg, 345 fathoms deep, and now to bo 

 particularly described. 



In this case there was the advantage and disadvantage of having to provide 

 everything for the express purpose of the ascending machine. A new wheel-room 

 had to be executed, new watercourses to be driven, new wheels to be built ; an 

 advantage, so far as the whole was perfectly adapted to the end in view ; a disadvantage, 

 inasmuch as the expense was very greatly increased. The fact, however, proves 

 the importance attached to tho means of facilitating the miner's operations. Any 

 further mention of the arrangements for the necessary power, than that the mover is 

 water and the machine an ordinary water-wheel, over-shot, 42 feet in diameter, 4 

 feet on the breast, making from two to two and a half revolutions per minute, is un- 

 necessary. The letting-on of the water is regulated from the top of the shaft, where 

 there is a miniature machine moved by rods and gear, connected with the power- 

 ladder, indicating exactly the relative position of everything below ground. A system 

 of signals, too, has been adopted, by which most of the circumstances occurring in 

 connection with the working of the ladder can be immediately made known above 

 ground. The Spannschutze, a sluice or pen-trough of admirable construction, is ap- 

 plied to this wheel, as its load is very variable. The crank is 3 x 6 feet long, of cast 

 iron, and is attached by a connecting rod with framed rods that work the crosses at tho 

 shaft head in the usual manner. 



The method of hanging the ladders deserves attention, as it is perfectly successful 

 and very simple. In the history of the machines there have been several arrange- 

 ments tried, but this is tho last and considered the best. The power-ladders are 

 hung on the cross-head of a knife-edge by two iron slings, 6x2 inches. They were in 

 this ladder first hung by passing the ropes round a segmental frame, but the friction 

 of the knife-edge induced a continual bending of the rope ; through a very small 

 angle, it is true, but such, that under its effects the wires gave way at the end of three 

 months. This led to an arrangement by which tho ropes are bound between 

 timbers bolted and screwed together, and thus the whole hung to the things above- 

 mentioned. 



Perhaps the most efficient construction would be the passing the ropes round 

 an arched head, as was the connection between the beam of the steam-engine and 

 piston-rod of old, only passing the ropes over a greater segment than was or is 

 customary. 



The ropes at the top consist of 36 wires, viz., three ropes of 12 wires in each rope, and 



o2 



