238 M. Arago's Biographical Memoir of James Watt. 



this prodigy was produced. The god was made of metal. 

 The hollow head contained water to the amount of an amphora, 

 plugs of wood closed the mouth and another opening situated 

 under the forehead, and combustibles suitably placed in a 

 cavity of the cranium gradually heated the liquid. Speedily 

 the steam generated caused the plugs to spring with a loud 

 report, and then escaped with violence, forming a thick cloud 

 between the god and his astonished worshippers. It appears 

 also, that, in the middle ages, the monks found this to be a very 

 valuable invention, and that the head of Busterich has per- 

 formed before other assemblies besides those of the benighted 

 Teutones.* 



After these faint glimmerings of the Greek philosophers, 

 we must pass over an interval of nearly twenty centuries, 

 before we meet with any useful notions concerning the pro- 

 perties of steam. From that time onwards, experiments, pre- 

 cise, conclusive, and u-resistible, take the place of mere idle 

 conjectures. 



In the year 1605, Flurence Rivault, a gentleman of the bed- 

 chamber to Henri IV., and the preceptor of Louis XIII., dis- 

 covered that an iron-baU, or bomb, with very thick walls, 

 and filled mth water, exploded sooner or later when tlu-own 

 into the fire, if its mouth tvere closed, or, in other words, if you 

 prevented the free escape of the steam as it was generated. 

 The power of steam was here demonstrated by a precise 

 pioof, which, to a certain point, was susceptible of numerical 

 a]ipreciation,t whilst at the same time it revealed itself as a 

 dieadful means of destruction. 



* Hero of Alexandria attributed those sounds, the objects of so much 

 controversy, which the statue of Meninon produced when the rays of the 

 rising sun darted upon it, to the passage, through certain openings, of a car- 

 rent of steam, which the heat of the sun was thought to have produced, 

 at the expense of the liquid, which the Egyptian priests placed, it was 

 said, in the interior of the pedestal of the Colossus. Solomon de Caus, 

 Kircher, and others, have gone so far as to investigate the particular ar- 

 rangements by means of which the priestly fraud was palmed upon the cre- 

 dulous. It appears evident, however, that their explanations are errone- 

 ous, if, indeed, there existed any thing of the sort requiring explanation. 



t If some antiquarian think that I have not gone back far enough because 

 I commence with Flurence Eivault; and if> according to the statement of 



I 



