1 64 STEAM-POWER AND ELECTRIC-POWER. 



and the involuntary contraction of their muscles 

 exhibited the actual conversion of steam-power 

 into animal motive-power. While this was a 

 virtual repetition of Franklin's experiment for 

 showing the identity of lightning and electricity 

 from condensing vapors in the air, it further re- 

 vealed the identity of the latent heat of steam and 

 electricity ; and that this motive-power is literally 

 harnessed to our " Lightning Trains." 



The sudden disappearance of the extreme heat 

 of a sultry summer-day is accounted for by its 

 conversion into electric action, either by quiet 

 diffusion, or disruptive flashes of lightning. 



AMOUNT OF HEAT INSTANTANEOUSLY DISPERSED 

 FROM CONDENSING STEAM. 



The total heat in a pound of steam would 

 render a pound of iron red-hot, if it could be trans- 

 ferred to it. The following calculations may show 

 the great extent of latent heat suddenly diffused 

 by the condensation of steam. Estimating the 

 latent heat (not indicated by the thermometer) of 

 steam under the ordinary atmospheric pressure to 

 be about 966, and the additional heat at 300 (the 

 heat of steam under the pressure of seventy-five 

 pounds to the inch), there appear to be 1,266 of 

 heat embodied in the steam experimented upon. 

 If from this extent of heat be deducted the resid- 

 uary heat, as tested by the thermometer held in 

 the jet from the gauge-cock, at 120 Fahr., there 



