llg BULLETIN 173, U. S. NATIONAL MUSEUM 



long bolts passing through their axes and secured at the ends by 

 nuts. Each vertical row of horizontal and inclined tubes forms a 

 section and the various sections are joined together by a double 

 transverse pipe at the top and back of the boiler. Each inclined 

 tube is fitted with a small circulating pipe extending through the 

 axis of the main pipe "to allow the colder particles of the water 

 in the main pipe to separate from the warmer particles and return 

 through the smaller pipe to the lower end of the main pipe." 



BABCOCK AND WILCOX BOILER, 1876 

 U.S.N.M. no. 309868 ; model ; gift of the Babcock & Wilcox Co. ; not illustrated. 



This is a half-size model of the boiler that won the award for sec- 

 tional steam generators at the Centennial Exposition in Philadelphia 

 in 1876. It was in service until recent years and is now preserved by 

 the Babcock and Wilcox Co., the makers. 



The boiler represented is a hand-fired, inclined-tube boiler, with 

 two parallel longitudinal drums connected by a cross steam drum. 

 The headers are of the earliest type of cast-steel sinuous header and 

 are seven tubes high. The boiler is suspended from two cast-iron 

 arched beams that rest upon the side walls of the brickwork. The 

 highly ornamental cast-iron front is trimmed in gold paint. The 

 boiler is equipped with a ball-and-lever safety valve, three water- 

 level sight gauges, and a pressure gauge. 



The Centennial boiler was sold to the De Castro and Donner Sugar 

 Kefinery in Brooklyn, N. Y., after the exposition and was continued 

 in service until recently. 



BABCOCK AND WILCOX STEAM GENERATOR, 1876 



U.S.N.M. no. 308690 ; original patent model ; transferred from the United States 

 Patent OflSce ; not illustrated. 



This model was submitted with the application for the patent 

 issued to George H. Babcock, of Plainfield, N. J., and Stephen Wilcox,, 

 of Brooklyn, N. Y., April 4, 1876, no. 175548. 



The model represents the typical elements of an inclined tube, 

 horizontal longitudinal drum boiler upon which are shown the mode 

 of mounting and supporting such boilers and the provisions for 

 making the connections of the parts that are the subject of the patent. 



The drum of the boiler is represented as having cast-iron ends, 

 each of which is formed with a stout horn near the top adapted to 

 receive a suspension link from a cross girder resting upon columns 

 at the sides of the boiler. Each end casting is further provided with 

 a series of holes near the bottom properly adapted to receive tubes 

 joined thereto by the process known as ex]:)anding. These tubes at 

 front and back are joined to the vertical tubes rising from the water- 

 tube headers by means of hollow castings in which hand holes are 



