86 Henry Riddell on 



perpetual motion device specifically named in the " Budget of 

 Paradoxes.^' and de Morgan's indignation at the unauthorized use 

 of his name can be imagined. 



The invention consists of a cylinder, shown in section, and 

 fitted with a piston of cylindrical form. The recesses shown are 

 formed in the internal surface of the cylinder, and are filled on 

 one side, where hatched in the sketch, with a heavy liquid, while 

 a vacuum is maintained in the corresponding chambers shown 

 unhatched. Of course, said the inventor, the internal piston 

 tends to float upward on the side where the heavy liquid appears, 

 and to fall on the side of the vacuous recesses. Hence a con- 

 tinued and forcible rotation ensues. 



Even by the fiasco of this failure the inventor was not de- 

 terred, as in 1857 he obtained a patent (No. 958) for an engine 

 with capillary tubes; in 1858 (No. 2563) he transforms the static 

 pressure of a column of water into dynamic pressure without loss 

 of water, while in 1859 (patent No. 2859) he proposes to alternate 

 the weight of a column of water upon the end of a balanced beam. 



The last invention is curiously paralleled by an Irish inven- 

 tor, Benjamin Glorney, in 1852 (No. 1189), where motion is to be 

 obtained by running a weighted carriage from end to end of a 

 balanced lever. 



14. Picciotti's patent. No. 1413 of 1859. The print in the 

 text, photographed from the drawing accompanying the patent 

 specification, proposes to do in 1859 exactly what Predavalle 

 imagined he had accomplished in 1858, — transform the static 

 pressure of a column of water into dynamic without loss of water. 

 The vertical pipe shown contains a tall column of water or other 

 heavy liquid, which also, by means of the hollow water chests 

 shown, fills the four sets of thin-walled curved tubes. The 

 inventor provides self-acting valves, indicated in drawing, by which 

 the pressure is cut off from pairs of these tube chests alternately. 

 Suppose a set of tubes to be in the position cjf extreme curvature, 

 and their corresponding sets, above or below as ihe case may be, 

 to be api):o.\i mutely straight. This corresponds to pressure upon 

 the straight tubes and no pressure upon the curved. If qow the 



