466 



TRA^'SACnONS OF THE AMERICAN INSTITUTE. 



The engines of the boats are two in number, with cylinders of fourteen 

 inches diameter and twenty-four inches length of stroke, working steam 

 expansively, furnished with snrface condensers and regenerators, by which 

 not onl}'- the boilers are completely supplied with fresh water, but a suffi- 



5_3j_ 



0J 





"^ c-^2 



cient additional quantity for all other uses for the consumption of 400 men 

 is attained. 



The boilers are four in number, and have 1,260 feet of heating surface 



