174 TlMEHRI. 
of logie-dried megass. Sugar decomposed io'8 lbs. =4 lbs. of carbon 
Water evaporated 447 lbs. ( which could 
1U , , ,. 1 have been eva- 
4 lbs. carbon x &2 = 2 4 '8 lbs. water j porated by the 
C sugar. — 
I9"9 lbs. excess of water evaporated in the 
logie. Logie-dried megass is here assumed to contain i8 - 86 0/0 of 
water. By taking 6'5 and 6'8 as the co-efficients of evaporation of 70 
and 75 0/0 crushing megass respectively, we find by a similar calcula- 
tion that an excess of 144. lbs. of water for 70 0/0 crushing megass 
and 9/1 lbs. of water for 75 0/0 crushing is evaporated by drying 100 
lbs. of the megass in the logie. It can thus be concluded that there is 
always some waste of fuel, however well the megass may be crushed. 
Some may argue, that the co-efficient of evaporation of the carbon is 
taken at too low a figure and that therefore the waste appears greater 
than it really is, but it is found that these figures very nearly approach 
the result obtained in practice. Even if we were to assume that 1 lb. of 
carbon could evaporate 9 lbs. of water, about the best average result, 
that has been obtained, with good fuel, there would be an excess of 
water evaporated in the logie of 87, 5'3 and 2"4 lbs. respectively for 100 
lbs. of 65 0/0, 70 0/0 and 75 0/0 crushing megass. This is however 
contradicted by the deductions made by Mr. Russell from his experi- 
ments, and he claims 17 0/0 in favour of the green megass. There is 
no doubt that these experiments were carefully made, but I cannot 
agree with Mr. Russell as regard his deductions. The 17 per cent, 
which he gives in favour of the green megass is not due to the value of 
this megass as fuel, but to the greater efficiency of Coster's Furnace 
compared to the furnace, in which the dried megass was burnt. 
A further examination of the results of the experiments with logie 
megass will show this. Here it has been found that 4^3 lbs. of water were 
evaporated to the pound of carbon. This is really a very poor perfor- 
mance and there is no doubt, that if this megass was burnt in the Cos- 
ter's Furnace, an evaporation of 7-8 lbs. of water per pound of carbon 
would have been obtained. Mr. Russell would add a great deal to his 
already valuable experiments, were he to make a trial with logie dried 
megass in the furnace used for the experiments with green megass. The 
furnace in which the dried-megass was burnt is of a very good type, 
compared to the furnaces mostly used for this purpose. Mr. Russell's 
figures also point out the great waste, accompanying the burning of 
dried-megass in the furnaces, which are generally in use. Let us now 
