1824.] On Steam-Engines. 355 



them of those accessary circumstances, which frequently pro- 

 duce the greatest effect on the minds of the vulgar and ill- 

 informed. 



Whenever man accumulates natural powers to effect certain 

 purposes, they may, by mischance, be diverted from their proper 

 courses, and become the cause of serious accidents ; and no 

 machine, by which those powers are concentrated, was ever 

 constructed that has not its peculiar dangers. 



To wish to employ only such machines as might be secure 

 from the consequences of want of skill, imprudence, and rash- 

 ness, were to wish to deprive ourselves of the happiest fruits 

 of human skill and industry ; at the same time it were a culpa- 

 ble neglect to suffer any man, for the sake of attaining an end 

 of secondary importance, to employ means which might obvi- 

 ously endanger the lives and property of his neighbours. In 

 such a case, public authority has a right to interfere, and exer- 

 cise a beneficial and protecting influence. 



Does this observation apply to steam-engines in general, or 

 only to a particular class ? Should the use of high and mean 

 pressure engines be restricted to certain situations ? 



The British Parliament has lately taken this subject into 

 serious consideration, and has adopted most of the precautions 

 recommended by a Committee of the House of Commons, 

 appointed to inquire minutely into it, particularly with the view 

 of obviating the dangers to which steam passage-boats are 

 liable from ill-constructed machinery, carelessness, or misma- 

 nagement. The Committee particularly recommended, that the 

 boilers of the steam-engines shall be made of wrought iron or 

 copper, and furnished with safety valves, of proper size and 

 form, one of which shall be so secured as to be inaccessible to 

 the workman who has charge of the engine : it also recom- 

 mends that this valve shall be loaded only with such a weight 

 that the pressure shall never exceed one- third of that, which 

 the boiler has been found, by actual trial, to be capable of 

 supporting without bursting, or one-sixth of its calculated 

 strength ; and that any person overloading the valve shall be 

 liable to punishment. 



Although the British Legislature has not forbidden the use 

 of high pressure steam-engines, either in passage-boats or ma- 

 nufactories, the preference has been given, especially for boats, 

 to low pressure engines; and much prejudice hasLeen excited 

 against the former from deplorable accidents which have occur- 

 red in America, in England, and France. Mr. Evans, however, 

 according to Mr. Marestier, has defied his opponents to produce 

 a single instance of the explosion of one of his engines, although 

 they work with a pressure of 10 atmospheres. 



But serious accidents are not confiued to high pressure 

 engines — they have happened with those of low pressure, both 



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