718 Transactions of tee American Institute. 



instance; and they have to stand no more heat than in other kinds 

 of boilers in common use. The fact of its being composed of 

 uniform parts, any one of which can be removed with little trouble 

 or expense, is greatly in its favor. We see, almost daily, boilers of 

 the old style taken but and replaced by new ones, for fear of their 

 being unsafe; or that they may be weakened in some part by burn- 

 ing away, corrosion or other causes, which it is well known often 

 occurs, and is in many cases impossible to detect. Nine-tenths of 

 the boiler may be perfectly sound; but from the fear that a weak 

 point may lead to an explosion, the whole is disciu'ded. In the 

 safety boiler no such danger exists; the defective part can be 

 replaced, and sound parts ret^iined for further use. 



Thus the strength of all parts of this boiler can l^e maintained at 

 its highest point for a much longer term of years than in the com- 

 mon forms, and with but slight expense, if any. When a change in 

 size of boiler is required, and small boilers are replaced with larger 

 ones, or the contrary, the old boilers ai-e of little value, as no one 

 will give much for a second-hand boiler; Avhile the safety boiler 

 may be used as a component part of a larger one, or be divided 

 into smaller, as the case may require, all of which is in favor of its 

 lasting value. 



SCALE AND SEDKIENT. 



As this matter of scale and sediment is the greatest difficulty met 

 with in steam engineering, and more loss, ti'ouble, and danger 

 occurs from this cause than from any other, I wnsh to have the 

 points of superiority of this boiler thoroughly understood, and it 

 will be much to the interest of those owning steam boilers, of any 

 form, to see that those having them in charge attend properly to 

 this matter. 



Practical engineers have noticed that wherever, in any boiler, 

 there is a strong and constant current, at that point the sheet or 

 tube remains clean and free from incrustation. The circulation of 

 the water through all parts of this boiler is very rapid, and our 

 experience with those of our boilers that have been in use the 

 longest shows that they possess this valuable feature of remaining 

 free from scale, and the deposit of sediment in the tubes, to a 

 remarkable degree. 



We claim this boiler to be superior to am' other known form, in 

 the ease with which it can be thoroughly cleaned, if, through neg- 

 lect, it becomes incnisted ; and if, through such neglect, any 

 damage should be done to any part, it can be renewed with a 



