Report of Society's Meetings. 183 
I venture to think the few remarks that follow will prove an assistance 
to some and of interest to all in the study of the subject. 
Combustion seems on first thoughts most complex, but in fact is one 
of the simplest of chemical phenomena. Each element of a fuel com- 
bines in known proportions with oxygen during the process of burning 
or oxidation, so that the amount of oxygen (or air containing that 
oxygen) necessary for the complete combustion of a given weight of 
fuel is ascertainable, and from this is found the weight and volume of 
the products of combustion. The energy or "heat" evolved by such 
chemical combinations is also known, and is convertible into an equiva- 
lent of work, if, however, there be any circumstance, such as water in 
the fuel, that will detract from the usefulness of this heat, we have 
merely to calculat e the amount of chemical energy expended in over- 
coming the adverse circumstances so as to be enabled to compare the 
effectiveness of good and bad fuels. 
I will confine myself entirely to the effect moisture, in the fuel under 
consideration, has upon conbustion. 
There are many ways in which the detrimental effect is made appa- 
rent, viz., upon the draught, and temperature of combustion, and the 
number of units or heat available for work. 
The moisture has to be evaporated at the expense of a portion of the 
fuel, and heated still further to the temperature of the other products 
of combustion. In this form it occupies considerable space, and in- 
creases the volume of the gases to be carried off, consequently a greater 
draught is necessary to maintain an adequite influx of air through the 
fire bars, yet by increasing the draught the gases will part with less 
heat in transit. The obvious remedy for this is to have a larger chim- 
ney and an increased sectional area of all the flues, the draught being 
increased in volume, not speed. 
A given weight of canes yields a certain weight of combustible 
matter, plus a variable weight of water, according to the quality of 
the crushing, so that when comparing the combustion of green with 
that of dry megass, we must consider the equivalent weight of the 
green megass to be that of the dry, plus the percentage of water con- 
tained, that is, 2 pounds of green megass containing 50 per cent, mois- 
ture, must be comparable with 1 pound of dry megass ; the 2 pounds 
of green megass, however, carry only 1 pound of combustible matter, 
and a portion of it has to be appropriated to evaporate the pound of 
water, the actual temperature is, therefore, considerably below that 
