METHODS OF EVAPORATION. 



33a 



Mate XXXIV. 



THE STUBBS EVAPORATOR. 



Plate XXXIV represents the Stubbs Evaporator. The upper cut shows the pan with 

 two compartments. The first occupies three-fourths of the pan; the second compart- 

 ment the remaining fourth. The juice enters the first compartment near the smoke- 

 stack in a regular stream, passing around the circle over the fire-box to cross-parti- 

 tions, where it thickens to a semi-syrup. Being over the hottest part of the furnace, 

 it raises to a light foam, which breaks to the lowest point where the cool juice enters, 

 not only keeping back the green scum, but carrying all the scum off of thirty feet sur- 

 face, where it is scraped off without loss of sweet. The semi-syrup is turned into the 

 second compartment at intervals, to be finished under full control of heat governed by 

 dampers. When done, to be run off with scraper, letting semi-syrup follow. Boil rap- 

 idly with two inches juice in order to cleanse well. 



The lower engraving represents the furnace. Should be built of brick, with eight- 

 inch wall fourteen inches above fire-grate: the balance seven inches. A sectional arch 

 with one damper in center, hinged at the back end to swing to back wall; also dam- 

 per across the mouth of left flue. The smoke-stack stands back, as the cut indicates. 

 The smoke-stack should be sixteen feet high, fourteen inches diameter. 



