204- Reply to ReJiiarks on Mr. Perkinses 



from their extreme smallness, must soon burn out; and the 

 reason given is, that all tubular boilers heretofore have been 

 liable to that objection. I will state the causes which occa- 

 sion this effect, and then show why my apparatus is not liable 

 to it. 



The cause of the tubular boilers upon the evaporating and 

 open-cistern systems burning out, is the want of some means 

 of keeping the water in contact with the tubes which are 

 exposed to the immediate action of the fire ; for if the tubes 

 have nothing but the weight of water and of the atmosphere 

 to press upon them, the water will be driven out of the tubes 

 by the superior tendency of the fire, when it burns with 

 intensity, acting upon the tubes to repel it : and, thus, every 

 every time the fire is brisk, the tubes get red hot, and very 

 soon burn out. Now, my invention directly meets this 

 defective point ; for, as the apparatus is closed in all parts, no 

 sudden heat can overpower the tendency of the water to cir- 

 culate in contact with the tubes ; for, if the heat is accelerated 

 sufficiently to cause a tendency of the water to fly off, it meets 

 with a reaction just equal to its action; and, therefore, it 

 counteracts that tendency of the repellent power of heat in 

 the same proportion. Thus, that which is a fatal objection to 

 all tubular boilers with open reservoirs is to my system one 

 of its greatest advantages ; for it causes the heat to circulate 

 more rapidly, and, consequently, to a greater distance, than 

 can be done by any other system. 



The fourth, and most serious, objection urged against my 

 system is the liability of the pipes to burst. This 1 will meet 

 openly and fairly ; and I think I can prove that it is less liable 

 to serious accident than the open-cistern system with a close 

 boiler. I could mention a great number of facts respecting 

 accidents from the open system ; and one object of my im- 

 provement was to remedy such accidents. But one strong 

 illustration, which I shall subjoin, will be sufficient to show 

 that such an accident may occur even with an open cistern. 

 I refer you to the letter of Mr. Carpmael, Patent Agent of the 

 Patent Office, Lincoln's Inn. From this gentleman's letter, 

 and the accompanying diagram, you will perceive how he 

 exploded a boiler with an open reservoir, and the reason 

 why it may and does often occur ; the effect taking place 

 upon the same principle on which low-pressure boilers are 

 exploded. The means which my apparatus possesses of 

 obviating this defect is, the power I have of making the tubes 

 strong enough to resist any possible pressure. For instance, 

 the present tubes which I make are proved to bear 3000 lbs. 

 to the square inch : and when it is considered that, to acquire 



