356 On Sleam-Engines. [Nov. 



in England and America ; and more than once, explosions 

 occasioned by the latter have been attributed to the former. 



An account is given by Mr. Stevenson, in the Edinburgh 

 Philosophical Journal,* of a dreadful explosion which oc- 

 curred near Edinburgh, of a high pressure steam boiler ; and in 

 France accidents have happened both with low, mean, and high 

 pressure engines, which require our particular attention. 



Explosions, which have cost many persons their lives, have 

 happened with what are called low pressure engines, but which 

 in reality cease to be such whenever the fire is strongly urged, 

 and the escape of the condensed steam prevented, either by the 

 accidental derangement of the safety valves, or by its being 

 purposely overloaded. Amongst others, we may mention the 

 deplorable accident which happened at Creusot, by which 

 many individuals were killed, by the bursting of the boiler of a 

 tow pressure engine. Let us turn to the other engines. AtPeronne 

 the balance beam of an English high pressure engine having 

 broken, the steam in the cylinder drove up the piston and its 

 rod through the planks and roof of the building in which it was 

 placed ; but no person was killed or hurt. 



At Paris the lower part of the boiler of a mean pressure 

 engine having split, the water flowed into the fire-place, and 

 put out the fire ; the walls of the furnace were not even shaken, 

 and no noise was heard except that of the rupture of the boiler. 

 A similar accident occurred about three years since in another 

 establishment, unattended by any more serious consequences. 



But at Essonne a more serious accident happened lately with 

 a mean pressure engine, the boiler of which had been cast at a 

 foundry not calculated for such work ; and it has been satis- 

 factorily proved, that the mischief was occasioned solely by the 

 clumsy construction of the boiler, and the faulty manner in 

 which its parts were put together. 



It results, from all the details which we have collected, that 

 no mean or high pressure steam boiler, constructed in any 

 regular establishment in France, has ever met with an explo- 

 sion ; although they are more numerous than those imported 

 from foreign countries. During the last year 36 of these en- 

 gines have been made in one manufactory at Paris, and a still 

 greater number are making in the present year ; and the more 

 they are used the more they are approved of. Since 1815 more 

 than 120 mean and high pressure engines have been made in 

 the French manufactories. 



Since 1815, 32 mean pressure engines have been sent to 

 St. Quentin, from one manufactory at Paris ; and the purchas- 

 ers are universally well satisfied with the service they perform. 



" Vol. v. p. 147- This boiler was erected for boiling the stills of the Lochrin Dis- 

 tillery, by high pressure steam. — C. 



