U. S. NATIONAL MUSEUM 



BULLETIN 173 PLATE 26 



2720: 13477A 



Boiler Accessories. 



1. Stevens safetv valve, 1825 (U.S.X.^^. no. 180029). See p. 119. 

 2. Babcock and Wilcox mechanical oil burner, 1929 (cutaway; U.S.N.-M. no. 309878). 



See p. 124. 



