774 TRANSACTIONS OF THE AMERICAN INSTITUTE. 



reduced the fuel used from 2,100 pounds per day to 700 pounds, 

 thus enabling me to do three times the work with the same fuel. 



In concluding, let me lay down a simple theory concerning the 

 cause of steam boiler explosions, which I do not claim as mine. 

 It is partly the theory of Dr. Ure, Zerah Colburn, Charles Wye 

 Williams, and several other prominent and eminently practical 

 men. In order to be rightly understood, I will commence at the 

 foundation. Neither water nor any other liquid, not confined so 

 as to prevent all expansion, can be raised in temperature by the 

 addition of heat without vaporization, that is, vapor is formed in 

 -all liquids as soon as heat is added ; and this formation of vapor 

 -continues in the liquid until the boiling point is reached, when . 

 the liquid, being saturated with such vapor, which it is unable to 

 retain by a succession of explosions, relieves itself of this addi- 

 itional vapor formed. It is for this reason that the boiling point 

 differs with the amount of pressure under which evaporation takes 

 ,place ; and also the reason why the temperature of all liquids 

 suddenly falls when they are stirred. The vapor is mechanically 

 set free, therefore it is evident that the pressure of vapor in the 

 liquid is the cause of the raising of temperature. When we stir 

 the contents of a boiling pot of milk or syrup, the boiling instantly 

 ceases, and the only change is a copious discharge of steam. If 

 the milk itself had been raised to the boiling point, no such effect 

 could be produced, as we do nothing to evolve it. 



Steam is an elastic vapor, and its pressure is due to the bulk or 

 number of atoms contained in a certain space. When a boiler 

 works under a pressure of forty-five pounds, the temperature of 

 the steam in the water is 290°. Now water, under atmospheric 

 pressure, cannot be raised to a temperature of more than 212°, 

 exceptino- when, by some means, it is kept perfectly quiet. In 

 such cases it has been raised to 21g°, but instantly falls to 212° a« 

 soon as ebolution commenced. It must be evident that the water, 

 being 815 times denser than steam, has the capacity of retaining 

 steam under, at least, the same pressure as that in the steam space ; 

 and that the steam contained in the same cannot be released until 

 either the pressure is relieved or its power to expand is increased 

 by heat. That this immense power stored in the water is the cause 

 not only of the rupture of the boiler, but of all the disastrous 

 effects produced, is now an admitted fact. The remedy, and one 

 that, under all circumstances, is a sure one, I claim to have dis- 

 covered. We all move here under an atmospheric pressure of 



