AMERICAN INSTITUTE. 569 



adverse, the train is heavy, and the steam is waning; the pulsa- 

 tions at length become ominously tardy, and on a sharp curve 

 while our engine is on its center, the giant stops for want of 

 breath. Such engineering, though it may occur every day, is 

 libelous, if not ridiculous. 



Suppose a locomotive to be standing at rest, there is no motion, 

 no noise, no appearance, save that of immovable solidity; sud- 

 denly, like a thunderbolt, a power is created, instantaneous, and 

 tremendous. The locomotive is torn into fragments; iron sheets 

 are ripped; iron bars arc rent and ponderous machinery is crushed 

 and mutilated like dry leaves in the gripe of a giant. Here is a 

 solution of the problem. Here is a commentary on the future 

 power of the steam engine. 



Now, what are the internal causes of these two phenomena 1 

 The one is understood as well as the other. In the first case, the 

 pressure is limited to 100 lbs., because some other engineers 

 adopt this standard; adverse wind retards combustion; cold feed 

 water chills and condenses; and at last, the friction and pressure 

 form a grand equilibrium. The result, ift rest. In the second 

 case, the water and steam being low, by the time the compliment 

 of steam has been quietly generated, the uncovered crown sheet of 

 tlie furnace has imparted to that steam, without augmenting its pres- 

 sure, several hundred degrees of heat. The safety valve suddenly 

 opens; there is a general tendency of steam and water towards 

 this vent; the super-heated steam absorbs the water, without 

 which it cannot expand, and its volume is, perhaps, ten, perhaps 

 fifty times increased. The result is a terrific explosion. These 

 are extreme cases; but there must be a safe and economical 

 medium. 



It may be urged, that since repeated attempts to use stame 

 (so called) have proved unsuccessful, by reason of the rapid de- 

 struction of the heaters, any nearer approach to using high steam 

 would be unprofitable. 



This crowning objection may be overcome by forming and su- 

 perheating by steam, in direct contact with the fuel. Experi- 

 ments with both steam and air, have proved this to be possible, 

 if not already feasible. 



Suppose a heater, or a firebox of a locomotive, surrounded with 

 water, to prevent radiation, to be supplied Avith enough fuel to 

 last six hours, and then made temporarily steam tight, by a sim- 

 ple apparatus now in use. Combustion being promoted by the 

 injection of air, a graduated quantity of water is thrown upon the 



