1020 TiiAXSACTioys of the American Institute. 



by strains due to unequal expansion caused by unequal heating of 

 different portions of the boiler ; or it may be due to corrosion from 

 long use or improper setting. 



The Baocock and Wilcox boiler being composed of wrought iron 

 tubes, and with a shell never exceeding thirty-six inches in diameter, 

 which shell is made of the best charcoal iron 5-lG of an incli thick, l)as 

 great excess of strength over any pressure whicli it is desirable to use; 

 and as the rapid circulation of the water insures equal temperatures 

 in all parts, the strains due to unequal expansion cannot occur to 

 deteriorate its strength. Should one of the tubes or T heads give out, 

 wliich is not at all probable, no explosion could occur, as has been 

 fully demonstrated by experiments ; and in case the water be allowed 

 to get 30 low as to overheat the shell, and cause it to give out, what 

 water remained would be confined to the tubes, and could not cause 

 a destructive explosion like the single large body of water in the 

 ordinary forms of boilers. 



Capacity. 

 The cubical capacity of this boiler, per horse-power, is equal to 

 that of the best practice in tubular boilers of the ordinary construc- 

 tion. The fire surface being of the most effective character, these 

 boilers, will, with good fuel and a reasonably economical engine, 

 greatly exceed their nominal power, though it is seldom economy to 

 work a boiler above its nominal power. The space occupied by 

 boiler and setting is equal to about two-thirds that of the same power 

 in tubular boilers. 



Convenience of Tkansportation. 



This boiler may be taken in pieces for transportation. The steam 

 and water drum is never over thirty-six inches in diameter, or more 

 than twelve feet long. The other parts may be readily handled by 

 one man. 



Experience with several hundred horse-power of these boilers in 

 operation, demonstrate fully all the above points of superiority. 



Mr. Montgomery said that it seemed as if we were traveling in a 

 circle ; the same things that were proposed years ago are now again 

 brought forward. He was in favor of government inspectors, who 

 can tell us what are really improvements. Many of our old steam- 

 ers used to do better work than our present ones. For instance, the 

 steamer "La Fayette," which was in the item of coal, much cheaper 



