BOIL Eli No. 3. 



73 



amounted to 2.4 per cent. Making allowance for this differ- 

 ence in the quality of the steam, the evaporation was increased 

 on the second test 3.5 per cent. Judging by the low tempera- 

 ture of the escaping gases, the boiler absorbed nearly the 

 whole of the heat of the products of combustion, and in this 

 respect the result obtained is all that could be desired. The 

 water evaporated per pound of combustible is less than the 

 best results obtained from boilers of the same type, using 

 Cumberland coal. It is inferred from the high proportion of 

 ash, that the coal was of an inferior quality, and that this fact 

 had much to do with the low degree 

 of economy. 



Boiler No. 3. 



Kind of boiler, . . . 



Number used, .... 

 Horse-power( collective, 

 basis 12 sq.ft. ), 



Kind of coal, .... 



f Horizontal return 

 \ tubular. 



Six. 



f Three hundred 

 \ and thirty-eight, 

 f Anthracite Lack- 

 \ awanna, broken. 

 Age, Six years. 



Boiler No. 3 consists of a plant of 

 six 48 inch boilers, set in one battery 

 of brick work, as shown in the follow- 

 ing cuts. The products of combustion 

 on leaving the tubes pass over the top 

 of the shells to the main flue at the 

 rear, and this arrangement provides 

 a small amount of heating surface 

 exposed to the escaping gases. There 

 is no provision for cleaning the tops of 

 the shells, and this surface is doubt- 

 less covered by a deposit of soot, and 

 thereby rendered inefficient. 



