" Multiple Evaporation." 



at which reje6led ; no matter what difference there is in 

 the details, or whether film or ordinary evaporation is 

 adopted. The following fafts from actual pra6lice, taken 

 from estates making mostly yellow sugar, will illustrate 

 this. 



On Aurora estate there is a triple built to an old 

 design in 1883, containing 3,000 square feet of heating 

 surface, having in the centre of each calandria an 8-inch 

 circulating pipe, and 12-inch vapour pipes (with no pro- 

 vision for circulation) conne6ling the vessels at one 

 spot in each calandria; the syrup is taken off with a 

 vacuum montejus, its usual evaporation is 3 lbs. of 

 water per square foot of heating surface, and compared 

 with more modern evaporators looks obsolete and defec- 

 tive ; but as a matter of fa6t, from a fuel and upkeep 

 point of view, this old fashioned triple with tortuous 

 passages will compare more than favourably with the 

 best work of the most modern evaporators in this colony. 

 The only disadvantage appears to be in the large amount 

 of heating surface embodied, and consequently high first 

 cost of the apparatus. 



At Perseverance d^ modern evaporator having 18-inch 

 circulating pipes, and efficient divided 18-inch steam 

 passages, also at Anna Regina, where the triple embo- 

 dies Mr. Chapman's well thought out improvements in 

 circulation ; double the work per square foot of heating 

 surface is done ; but the fuel cost for work done is prac- 

 tically the same. 



The successful working of the first "Yaryan" ere6led 

 here led many into expense and difficulty through ex- 

 pe6ling fuel economies from this and other film evapora- 

 tors that were quite impossible ; the writer well remembers 



A2 



