BOILER No. 51. 



185 



Dimensions of Boiler No. 51. 



Diameter of main shell, . . . . . . . 90 in. 



Diameter of drum and water leg, . . . . . . 29 in. 



Length of' main shell and tubes, 9 ft. 9 in. 



Number of tubes 2 inches outside diameter, . . . 248 



Area of water-heating surface, 941 sq. ft 



Area of steam-heating surface, . . . . . . 420 sq. ft 



Area of total heating surface, . 1,367 sq. ft. 



Area of grate surface, 45.0 sq. ft. 



Area through tubes, ........ 4.1 sq. ft 



Width of air spaces and metal bars in grates, ... 1-2 in. 



Area through stack, . . . . . . . . 8.7 sq. ft. 



Height of stack, . GO ft. 



Ratio of water-heating surface to grate surface, . . 20.6 to 1 



Ratio of steam-heating surface to grate surface, . . 9.3 to 1 

 Ratio of total heating surface to grate surface, . . .30 to 1 



Ratio of grate to tube area, 11 to 1 



Results of Tests. Boiler No. 51. 



