Dr Fyfe on the Prevention of Smoke, 8fc, 50 



The average of the above ten results, which includes that 

 given in the preceding table, is 11.62, from the average tem- 

 perature of 105 ; and supposing the water to have been at 

 32, then the average result would be 10.87. Or it may be 

 viewed in another way. In all the trials, 5576 lb. of coal were 

 used, and 63,590 lb. of water were evaporated, and 63590 

 -*- 5576 = 11.4, and reducing this from the temperature of 

 105 to 32, the result would be 10.66, and again 10.66 + 

 10.87 -r- 2 = 10.76 ; a result which exceeds considerably the 

 highest that has, so far as I know, been put on record — I 

 mean that of Henwood, which was 9.94, procured by English 

 caking coal, the evaporative power of which, compared to that 

 of Scotch coal, is allowed to be as about 4 to 3. 



With the view of ascertaining the power of the furnace and 

 boiler, without the use of the steam apparatus, similar trials 

 were made with the same coals, due attention being paid to 

 the different circumstances already stated. On an average, 1 

 found that for the consumption of each lb. of coal, the eva- 

 poration amounted to 6.66, and reducing the water to 32, as 

 before, the result would have been 6.17. 



These results were still farther verified by noting the con- 

 sumpt of fuel, during different periods of the day when the 

 furnace was in use, with and without the steam apparatus. 

 The following are the results : — 



During the periods stated in the above table, the engine 

 connected with the boiler was all the time doing the same 

 work ; and consequently we have so far an indication of the 



