Perpetual Motion 85 



continuous motion takes place. The invention was anticipated 

 by a patent granted to Count de Thivelle in 1821 (No. 2472), and 

 perhaps by that taken out in 1662 (No. 139) by Toogood and 

 Hayes for draining difficult situations by means of sponges. 



Fig V. — Predavalle's Patent, No. 6510, 1833. 

 Floating Piston. 



13. The curious patent of Bartholomeo Predavalle, No. 6510 

 of 1833. This is chosen for illustration because of its connection 

 with a very interesting and famous man. 



'Vo develop and work this invention a company was formed 

 and a prospectus issued, promising incredible profits to the share- 

 holders and giving the name of Augustus de Morgan as one of 

 the directors. This project is, as far as I can remember, the only 



