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" Multiple Evaporation," 



By William Price Abell, Wh.Sc., Assoc. M. Inst. C.E. 



INCE the efficient cycle of evaporation intro- 

 duced by RiLLlEUX in 1830, or more cor- 

 re6lly speaking by Pecqueur in 1829, no 

 one appears to have put forward a satisfa6lory expla- 

 nation of the unequal distribution of heat between the 

 units of multiple evaporators, and, as clearly pointed 

 out in Mr. Scard's interesting paper on the subje6l, we 

 are not yet in possession of all, or even sufficient fa6ts 

 and data on which to base a satisfa6lory theory. 



Willi our present knowledge of this subje6l we are 

 very much in the same position with regard to a satis- 

 faftory explanation of the behaviour of " Multiple Evapo- 

 ration" that Engineers were, for a hundred years 

 after HORNBLOWER in 1781 introduced his Compound 

 Engine, before finding a theory that satisfa6lorily ex- 

 plained its established efficiency. It is now a matter of 

 history that only a little over ten years since, was data 

 available to prove that the efficiency of the Compound 

 Engine was due to the redu6lion of the variation of 

 pressure and temperature in each cylinder, this not only 

 reducing the amount of liquification but by re-evaporating 



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