MULTIPLE EFFECTS. 357 



meut, great economy is secured in the use of fuel, and that the expense 

 of attendance during the concentration of the juice is greatly dimin- 

 ished. 



The saving of labor secured by the employment of triple effect ap- 

 paratus, as shown in the working of two similar estates, is as given in 

 " Sugar Growing and Eefiuing," page 271, as follows: The syrup and 

 sugar produced upon each estate were said to have been identical iu qual- 

 ity and value, and both were under equally able management. On the 

 estate using open evaporators and a single vacuum pan, the labor 

 amounted to 58 men for 18 hours per clay, or 1,044 hours per day; while 

 the second estate, using a triple effect and vacuum pan, required, per 

 day. 40 men for 13 hours, or a total of 520 hours of labor per day — a 

 saving of labor, as will be seen, of one-half. Each factory turned out 

 daily 13 tons of first and second sugars. The additional expense of the 

 plant is obvious ; but if this saving may be counted upon as possible, 

 the employment of this triple effect appears by far the most economical. 

 Only such juice as has been purified to such a degree as to yield no 

 impurities upon further concentration, is adaped for use in the triple 

 effect, since it is impossible that these can be removed by skimming. 

 The several pans of the triple effect are connected with each other in 

 such way as to enable the contents of the first to be drawn into the 

 second, and the second into the third, as the proper degree of concen- 

 tration is attained in each. 



