62 TlMEHRI. 
centration of the juice giving one hhd. of sugar, is 
theoretically just sufficient for the diffusion of another 
hhd. In practice it will be more than sufficient, because 
the loss of heat by radiation, which we considered when 
estimating the coal consumption, will give so much more 
condensed water. The boilers would be fed with cold 
water from the trenches, which would be distilled over 
into the various steam pans, whence it would be sent to 
the diffusers. Observe that this feeding of the boilers 
with cold water does not involve a waste of fuel, if the 
hot water be returned as promptly to the diffusers as it 
would otherwise be to the boilers. The steam which had 
passed through the engines should be condensed in 
separate vessels, say the battery heaters and clarifiers, 
and not used for diffusion, as it would contain grease and 
other harmful matters. But the evaporating vessels 
alone will give sufficient water, of the best possible des- 
cription, being free from substances in solution. It is 
the water that the estates' people drink when grinding is 
going on in the dry season ; it is obtained in the same 
manner as that made on coolie ships, transports, &c, 
and it is in the proper quantity with just that excess 
which is desirable to remove all anxiety about running 
short. 
There is another matter in connection with this sub- 
ject which deserves attention. It has been suggested, 
with some show of reason, to diffuse the megass after it 
leaves the mill, and so obtain the residue of sugar which 
the mill fails to extract. 'It is easy,' argue the advo- 
cates of this method, f to extract a fair percentage of 
juice by crushing, with a moderate expenditure of 
power. First then obtain this amount, and then submit 
