88 



Vh rough which the steam for the rhambers passes. 

 The syrup in boiling sometimotimes escapes by the 

 escape valve ; this syrup remains in the column and 

 is taken up ugain. Without these columns, the syrup 

 would be lost, A spirit glass shows the quantity in it. 



10. BOILING APPARATUS. 



The construction and working of the boiling ap- 

 paratus rest on the same principles as the evaporating 

 machine ; I will not then have to enlarge on the 

 subject. This apparatus is composed of the boiler, 

 condenser and air pump. The heating is performed 

 by three isolated superimposed coils. It is furnished 

 with a taster whi' % h goes into the in.-'fk i and bj 

 which samples of syrup are drawn out. 



11. TUHIUNE OR CKNTRIFrfrAL. 



The turbine is a machine which is used instant- 

 am-ously and mechanically to drain and dry the su- 

 gar, that is to say t.-> isolate the crystals from the 

 liquid. The construction of this in.-i chine is based 

 upon this principle in physics: ail bodies having 

 a circular motion tend to fly off at a tangent from 

 the centre. The turbine is composed of a drum open 

 at the top, provided with very fine wire cloth on its 

 inside surface. This wire cloth is fastened to a solid 

 iron frame of sufficient weight to give considerable 

 intensity to the centrifugal force. The drum is pro- 

 vided below with a pivot solidly fixed into a collar 

 fastened into the base. This base serves as a cover- 

 ing for the drum. 



The turbine in motion runs 1000 to 1200 revolu- 

 tions per minute. 



