Perpetual Motion 79 



Gravesande examined the machine most minutely as far as its 

 exterior was concerned, and was perfectly confident that no means 

 existed for communicating motion from the outside. It was said 

 that Orphyreus refused an offer of 80,000 crowns from an English- 

 man for his secret, and was so much alarmed at the visit and 

 examination of Gravesande that he smashed the machine to pre- 

 vent its construction from becoming known. Neither in England 

 nor on the Continent did faith in this wheel readily die out, and 

 the curious reader will find in the ^'' Antmal Register^'' of 1760 a 

 correspondence from which I have obtained the copy of 

 Gravesande's letter which I have used. It will be noted that the 

 correspondent had complete belief in the success of the con- 

 struction. 



Since this date no perpetual wheel has caused much dis- 

 cussion among scientific men, though two inventors have had 

 rather singular honour paid to them. 



About a century ago one construction is said to have been 

 the subject of an enquiry instituted by Cardinal Ilgolino, Legate 

 of Ferrara, who nominated a commission of Engineers and Philo- 

 sophers to examine and report upon the design. 



The report was said to be highly favourable, but is scarcely 

 worth quoting now as its origin is historically doubtful. 



The other case referred to was in America, where in i8i8 a 

 fake machine was exhibited by a man named Redhefter. This 

 machine caused a commotion in Philadelphia, so much so that a 

 committee was appointed by the State Legislature to investigate 

 its claims. In the ^'' Journal of the Franklin Institute" the Editor 

 asks the question — " On which side were the scientific men of 

 Philadelphia when Redheffer's machine was exhibited on Chest- 

 nut Hill "? He proceeds — "Those who recollect the period will 

 have no difficulty in answering the question. We believe that 

 nineteen-twentieths of those that were so esteemed were avowed 

 believers. We know one gentleman who professed, and was 

 believed to be a man of great mechanical knowledge, who delayed 

 in completing a patent lest Redheffer's machine should prove a 

 success." 



