ECONOMY OE FUEL EOB STEAM MACHINERY. 343 



quantity of fuel used, and the quantity of water, been carefully noted, 

 the experiment would have possessed much greater value ; as it is 

 however, it is sufficient to excite enquiry. It is not improbable that 

 electricity may exercise an influence in converting water into steam, 

 which has never been assigned to it, and we may yet live to see the 

 combined action of electricity with heat and water produce as great 

 an extension of the application of steam power as was effected by the 

 improvements of James Watt. 



Mr. Harshman's theory is : that water contains a large amount of 

 latent heat, which, under some circumstances is capable of being 

 rapidly and dangerously developed, and under others, of being gradu- 

 ally freed without danger, and that to accomplish this it is necessar}' 

 to establish an electric or galvanic equilibrium in the boiler. That an 

 iron boiler, covered in all but its fire surface and flues, with a copper 

 coating, generates steam very rapidly, saving half the fuel, and cannot 

 be exploded. It may rupture by over-pressure and relieve itself by 

 allowing an escape of steam, but it cannot explode. The correctness 

 of this theory Mr. Harshman says he has illustrated by repeated ex- 

 periments, in every one of which the result has been uniformly satis- 

 factory. Having satisfied himself on this point, he is now taking 

 measures to bring his discovery and invention to the attention of the 

 piiblic, very justly believing that it will be properly appreciated so 

 soon as sufficient evidence is furnished of its efficacy to prevent the 

 recurrence of a species of calamity highly destructive to life and pro- 

 perty. 



The following details of the experiments carried on by him are 

 from the Railroad Record of the Railway Times, 



" The experimental boiler employed was a small cylinder without 

 flues, twelve inches long and eight inches in diameter. The cylinder 

 was made of iron 29 inches thick, and the ends somewhat thicker. 

 The seams were riveted and soldered, and the safety valve fastened to 

 the boiler by solder. The furnace was of common construction, with- 

 out return flue. The boiler was placed in a strong frame of iron, the 

 ends being confined, one by a bar extending across the end, and the 

 other by a square piece of iron in the centre. One half the surface 

 of the cylinder was exposed to the action of the fire, the other half 

 was covered with copper. The ends were also covered with copper. 

 The safety valve was confined by a long wire attached to a spring 

 balance. The fuel employed was hickory wood well dried. The boiler 

 being placed in such a position that its explosion could do no damage, 

 the fire was lighted, and the observers withdrew to a distance to ob- 



