SUGAR. 



181 



10° Beaume collectively, tlie yield of all sugars at the ascertained 

 rate would be 6744 lbs. jyev hour. From my observations, it appears 

 that the water to be evaporated in boiling down the second and third 

 sugars — including one gallon of water added to each centrifugal 

 charge — amounts to 60 per cent, of the weight of the totally- 

 finished sugars, or to 405 gallons per hour, to which must be added 

 10 per cent., or forty gallons for loss by radiation, &c. 6000 gallons 

 of raw juice at 72° temperature, when clear of its scum and reduced 

 in volume by five minutes' boiling in the clarifiers, would become 

 5476 gallons of clarified juice sent down to the concentrators at 72° 

 temperature, and would contain 11,700 lbs. absolute sugar, which, 

 at the specific gravity of 1*6, would measure 731 gallons. It was 

 ascertained that, in the first sugars sent down to the coolers, the 

 saccharine matter was associated with water amounting to 80-4 per 

 cent, on the yield of all sugars, or 205 gallons per hour. In this 

 manner (541+405+40 + 731+205) 1922 gallons of the juice have 

 been disposed of, leaving 3554 gallons to be evaporated, one part 

 in the vacuum pan being at the expense of the steam raised from 

 the other in the concentrators. Allowing 10 per cent, on the total 

 amounts for loss and waste, the quantity should be divided in the 

 proportion of 60 per cent, to 40 per cent., leaving thus 1422 gallons 

 to be evaporated in the vacuum pans hj 2132 gallons, converted 

 into steam in the trays. There is then in the syrup ready for the 



trays : 



Galls. Galls. 



Saccharine matter . . 731 



Water associated with first boiling 205 



Water evaporated in vacuum pan 1422 



Total syrup 2358 



Water evaporated in concentrators to produce 



power, and boil second and third sugars , . . . 986 



Water evaporated to boil first sugar 2132 



Total evaporated in trays 3118 



Total clarified juice per hour 5476 



" The syrup, therefore, will form 43 per cent, of the clarified juice, 

 and if the latter gauges 10° Beaume, the former would indicate 21° 

 Beaume. Comparing this with the observations, it appears that 

 153,341 gallons of clarified juice were converted into 72,049 gallons 

 of syrup, both at 160°, the latter being 47 per cent, of the former ; 

 or if the juice stood at 10° Beaume, the syrup would have indicated 

 19° Beaume ; that is, rather less steam was actually generated in the 

 trays than the foregoing calculations indicate, which is accounted for 

 by the third boilings not having been made during the experiments, 

 and, therefore, that much less steam was required by the vacuum 

 pans. 



" These calculations agreeing so well with observations make it 

 probable that the latter were very accurate, and point to the result 

 that by utilizing the steam from the concentrators, the evaporation 

 of 57 per cent, of the juice only is necessary to convert the whole 

 into sugar and the residuary molasses. For the third boilings, quiet 



