97 



In my calculations, I have not up to the present 

 taken into account the substances taken off in the 

 defecating and filtering processes and the losses in 

 sugar. All these taken into account will reduce 

 our 22,120 Ibs of boiled matter to 19,000 pounds. 



To reach this concentration, a vacuum is first 

 created in the machine by the use of the air pump, 

 and one half of the syrup to be reduced is put in ; 

 then steam is let into the first coil and water is let run 

 intothe condenser so as to have the vacuum main- 

 tained at 24 inches corresponding to a temperature 

 of 150; and the evaporation is continued until a 

 sample ! ..;.!^n up by the taster gives the crook proof ; 

 in get this proof, a little syrup is taken up between 

 the forefi.iger and thumb, which are then quickly 

 separated ; if a very fine slight .thread is formed 

 which breaks and tarns over upon itself in the shape 

 of a cork screw, the right degree has been attained. 

 Then the rest, of the syrup is put in, two hundredths 

 at a time (say in 25 times) as the mass reaches its 

 proof point and the vacuum is maintained to 18 inches. 

 Every time more syrup is introduced the mass must 

 be brought up to the hook proof. As the second and 

 third coils are covered, steam is necessarily intro- 

 duced into them and the vacuum is gradually raised 

 to 26 inches under a pressure of 50 pounds of steam. 

 The operation is finished with 28 inches of a vacuum, 

 that is a temperature of 130, by reaching the string 

 proof, which is arrived at when the thread in breaking 

 no larger turns upon itself in the shape of a cork 

 scrtw. 



