EXTRACTING BEET JUICE 435 



be determined accurately by chemical analyses of sample 

 stalks. Naturally, it is important to harvest when the 

 stalks contain the maximum quantity of sugar. Though 

 chemical analysis is more certain, the grower learns to de- 

 termine the best date for cutting quite accurately by the 

 appearance of the stalk and the stage of grow^th. For econ- 

 omy of production, it is desirable to continue the operation 

 of the sugar mill over as long a period as possible. As the 

 sugar content decreases quite rapidly after the maximum 

 is reached and after the cane is cut, planters extend the 

 season by planting varieties which ripen at different times, 

 by planting on different types of soil, or by extending the 

 planting season over a considerable period. 



The usual method of harvesting is to strip the canes and 

 cut them off close to the ground with a knife. Machines for 

 harvesting have been devised, but they have not proven 

 satisfactory. As the canes begin to lose their sugar rapidly 

 within 24 hours after cutting, they are usually hauled from 

 the field to the mill as soon as cut. Numerous methods 

 of transportation are in use, including boats, wagons, and 

 tramways. One of the most common methods in large fields 

 is the use of a light, movable track with cars drawn by a 

 small steam engine. The cane is usually loaded upon wagons 

 by hand ; it is then loaded into the cars by the use of a derrick 

 and is unloaded in the same way at the mill. 



597. Extracting the Juice. The juice is extracted from 

 the stalks by means of heavy rollers. The stalks are first 

 shredded by revolving cylinders set with numerous pegs or 

 spikes, and then pass between rollers which crush out about 

 75 per cent of the juice. They then pass on to another set 

 of rollers, on the way to which they are sprayed wiih the 

 heated juice from the third and last set The second set of 

 rollers removes about 10 per cent of the juice, and the stalks 

 then pass to the third set. On the way, the canes are sprayed 

 with hot water. The third set of rollers crushes out about 



