U. S. NATIONAL MUSEUM 



BULLETIN 173 PLATE 24. 



Sectional Boilers. 



1. Babcock and Wilcox steam generator, 1867 (model; U.S.X.M. no. 309837). See p. 115. 



2. Sinuous boiler headers, 1867-1926 (cutaway; U.S.X.M. nos. 309871-309875). See p. 117. 



