MECHANICAL PARADOXES. 



power without adding to it from any external 

 source. Another favourite endeavour has been 

 to produce power where there was none at all 

 without bringing it from any external source. 

 The two problems are essentially the same. 

 To make two pounds of lead out of one is quite as 

 hard as to make one pound of lead out of nothing 

 at all. It is really a task of that nature that 

 many inventors have set themselves. 



The most common device for making power 

 produce itself and maintain itself " with no 

 visible means of subsistence " is a mill on one 

 side of which gravity can act with greater lever- 

 age than on the other. 



Fig. 26 is a diagram of such an arrangement, 

 and represents the principle governing the 

 design of several such devices for which patents 

 have been taken out. 



A wheel has a number of jointed spokes, the 

 joints being capable of bending from the straight 

 line only in one direction, so that the outer limb 

 can hang straight down on the side on which the 

 spokes are rising, as at A B, but cannot fall 

 beyond the straight on the side on which the 

 wheel is falling, as at D E. At the end of each 

 outer limb is a weight, as at F G H. As the 

 spokes rise on the left, the joints bend and 

 allow the weights to hang down at a shorter 

 distance from the centre, thus diminishing the 

 leverage at which they act, and so reducing 

 their turning power. When the arms have 



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