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1 1 . That the loss arising from a scale of sulphate of lime 
of not more than iVth of an inch amounted to 14-7 per cent. 
12. That neither wet coals, nor coals which had been out 
of the pit for three years, nor wet weather, nor a variation of 
temperature in the atmosphere from 40° to 70°, produced any 
appreciable difference of result. 
13. That windy weather invariably gave a good result. 
14. That a comparatively thick and hot fire, with a good 
draught, uniformly gave the best result. 
15. That the difterence in the results obtained by a dif- 
ference in the coal used, all obtained from this immediate 
neighbourhood, amounted to a loss of 1 1 per cent. 
16. That the same coals, reputed to be from the same pits, 
will vary in their results as much as 6 per cent. 
17. That when a boiler is worked solely for the purpose 
of heating by means of its steam, dye vessels, soap cisterns, 
&c., if we take its available power with the steam at 2^ lbs. 
pressure as equal to 100, at 7 lbs. pressure it will be 120, 
and at 10 lbs. it will be 130; the same quantity of coals 
being consumed in each case. Or this surprising result, 
at present unaccounted for, may be thus stated : The same 
weight of coals consumed in the same number of hours will 
work ten cisterns with the steam at 2 ^ lbs. pressure, twelve 
cisterns at 7 lbs., and thirteen cisterns at 10 lbs. 
18. While we may reasonably look for improvements in 
the construction of the fire place, in the form of the boiler, in 
the addition of separate supplementary heating surface, and 
in cleanliness, and thereby effect great saving in the con- 
sumption of coals ; we can not at the same time expect 
much saving from extension of flue space when coated with 
soot, nor from a greater length of boiler than four times the 
length of the fire place. 
Mr. Graham stated that in consequence of the uniform low 
results obtained by evaporation from boilers and pans open to 
