76 THE CANADIAN NATURALIST. [Vol.'viii. 



sists of a pair of rods made of Norway Pine eight or nine inches 

 square, the pieces of timber being 20 feet or more in length, and 

 joined together by strong iron plates till the rods are 650 to 700 

 feet long ; below this depth to that of 1450 feet there is another 

 similar pair. At distances of ten feet apart platforms are placed, 

 so that when they come opposite to each other, and there is a 

 temporary pause, the men on those of the one rod step across to 

 the platforms on the other, constantly ascending or descending 

 as desired ; the platform being only large enough for two men 

 to pass. At the surface each rod is connected to adjacent ends 

 of two gigantic bobs or walking beams, each of 30 feet in length. 

 These two bobs are connected together by a strong wooden shaft, 

 and are attached to the steam-engine gearing and worked so 

 that the ends (two or three feet apart) have a reciprocating 

 movement of ten feet ; consequently any force tending to pull 

 one- bob down (as the rod loaded with men) will tend to lift the 

 other (or the unloaded rodi. Now the two rods are thus balanced, 

 and in order to lift men from the mines, only the amount of 

 steam to overcome their weight and the friction of the machine 

 is required. This is the principle, but in practice the rods 

 which come to weigh many tons, must be further balanced, and 

 also the friction existing between them and the inclined foot 

 wall must be relieved. About every twenty feet apart there is 

 a pair of flanged wheels attached to the rods and moving on rails, 

 while at every 50 or 100 feet there are permanently attached 

 grooved wheels, over which pass wire ropes or chains attached to 

 both rods, and thus the dead weight of each section is locally 

 balanced, and the upper part of the rods and the bobs are not sub- 

 jected to an almost breaking strain. Again, by means of the 

 break in the continuity of the rods above noticed additional 

 equilibrium is given to the whole contrivance ; for here the 

 rods of the lower half of the man-engine are attached to another 

 set of bobs at the opposite ends to those to which the upper set 

 is attached ; and thus when the rods are completely loaded the 

 men on the upper 700 feet going in one direction tend to balance 

 those on the lower 700, going in the same direction, and only 

 the friction of the parts has to be overcome by the steam, 

 besides the great weight of each rod being broken into two parts. 

 The man-engine makes four strokes per minute, there being a 

 pause at the end of each. The whole construction is very 

 costly, but it is the best means of transporting the men to and 



