54 



THE SEVEN FOLLIES OF SCIENCE 



" To amuse the hours of a long confinement from illness, 

 Sir William Congreve has recently contrived a scheme of 

 perpetual motion, founded on this principle of capillary at- 

 traction, which, it is apprehended, will not be subject to 

 the general refutation applicable to those plans in which 

 the power is supposed to be derived from gravity only. 

 Sir William's perpetual motion is as follows: 



" Let ABC, Fig. 12, be three horizontal rollers fixed in 

 a frame; aaa, etc., is an endless band of sponge, running 

 round these rollers; and bbb, etc., is an endless chain of 

 weights, surrounding the band of sponge, and attached 



to it, so that they must move together; every part of this 

 band and chain being so accurately uniform in weight that 

 the perpendicular side AB will, in all positions of the band 

 and chain, be in equilibrium with the hypothenuse AC, on 

 the principle of the inclined plane. Now, if the frame in 

 which these rollers are fixed be placed in a cistern of water, 

 having its lower part immersed therein, so that the water's 

 edge cuts the upper part of the rollers BC, then, if the 

 weight and quantity of the endless chain be duly propor- 

 tioned to the thickness and breadth of the band of sponge, 

 the band and chain will, on the water in the cistern being 

 brought to the proper level, begin to move round the rollers 

 in the direction AB, by the force of capillary attraction, 

 and will continue so to move. The process is as follows: 



