BOILER No. 48. 177 



low results which are often obtained on more modern boilers, 

 the performance here shown, must, under the circumstances, 

 be considered remarkable. Looking at Test No. 94, the 

 rate of evaporation exceeds anything ordinarily obtained from 

 boilers of approved type, and the temperature of the escaping 

 gases is correspondingly high, but the evaporative result, viz., 

 9.22 pounds of water from and at 212 degrees per pound of 

 combustible, is not more than 20 per cent, below the highest 

 that can ordinarily be obtained from the horizontal tubular 

 boiler with the class of fuel used. 



Boiler No. 48. 



Kind of boiler, Plain cylinder. 



Number used, . ... One. 



Horse-power ( basis 6 sq. ft. ), . . Seventy-seven. 



Age, Several years. 



Boiler No. 48 is of the plain cylinder type, arranged and 

 set in the general manner shown in the cut of Boiler No. 47. 

 Here four shells instead of three are used, and the setting of 

 the boiler is independent of other boilers. The proportion of 

 heating surface to grate surface is somewhat larger than in 

 Boiler No. 47, being 10.9 to 1, though very far below that of 

 good practice in approved boiler work. 



Dimensions of Boiler No. 48. 



Number of shells, . 4 * 



Diameter of each shell, . . ... . . . . 30 in. 



Length of each shell, 30.5 ft. 



Area of heating surface, 4(>4 sq. ft. 



Area of grate surface, 42.7 sq. ft. 



Area through flue, ......... 6 sq. ft. 



Height of chimney, 75 ft. 



Width of air spaces and metal bars in grates, Air 5-1G in., metal 3-8 in. 



Katio of heating surface to grate surface, .... 10.9 to 1 



Ratio of grate surface to flue area, 7.1 to 1 



