402 



FARMERS' REGISTER. 



[No. 7 



ulously avoiiied ; but Avhen all the Bcuni is remo- 

 ved the fire may be Ibrced, and aonceniration will 

 proceed rapidly. 



Duririj; the evaporation it always happens thai 

 the juice has at certain tin)ee a great pro|>ensity to 

 rise in the boiler. This disposition will be the 

 greater when the juice is not o(" the best quality, or 

 has not been well deiecated. However, all juice 

 is more or less subject to it. This rising is occa- 

 sioned by a number of bubbles, formed by the dis- 

 engagement oC the steam, and the resistance ofler- 

 led to it by the viscous nature oi' the juice. These 

 bubbles rapidly succeed each other, and form 

 such a head, that they would soon overfl''W the 

 boiler, unless means were taken to prevent it. 

 The simplest, is to throw in any fat substnnce, as 

 oil, suet, or butter, the last generally preferred, 

 which soon disperses the bubbles. It is sometimes 

 necessary to repeat this operation several limes du- 

 rinsr the process of concentration. 



To asceriain the period when the juice has arri- 



emptying ought to be performed regularly every 

 half hour, if the evaporating surfaces of the dit- 

 (erent boilers be rightly calculated; but if anything 

 should occur to prolong the operation, (from half 

 an hour to three quarters tor example,) it would 

 not affect the general result, such is the advantage 

 of the harmony in the arrangement above recom- 

 mended. 



In this evaporating battery, the scum should be 

 carefully removed during 'the process of evapora- 

 tion, and this is easily managed, owing to the 

 comparative smallness of the dimensions of the 

 boilers. Should the charging and discharging 

 take place every half hour, one may calculate on 

 working off in 15 or 16 hours 12,000 litres (up- 

 wards of 3,000 irallons) of juice. But if the work 

 20 on night and day, 24,000 litres (more than 

 6000 srallons) may be calculated on as the result. 

 Again, supposing that the year's work last 4 

 months, or 120 days, and that 70 per cent of juice 

 was e.xlracfed, it would require, to maintain a 



ved at a proper degree of concentration, and when { similar mnnufiictory, about two millions of kilo- 

 evaporation ought to cease, the areometer must be i grammes (1970 tons) in the first case, and double 



made use of These are the general features of 

 this operation, by whatever process it is accom- 

 plished. A few particulars follow, of details pecu- 

 liar to different systems and apparatus. 



1. The Customary Method of Concentration. 



Care having been taken to obtain the juice clear 

 from the defecation boiler, and proper attention 

 paid to skimming the li(|uor, management of the 

 fire, &c., as has been described, the suiiable point 

 at which clarification should begin ought to be 

 particularly attended to. This, according to the 

 rule generally adopted, is at 26*^ of Beaume, boil- 

 ing, or 30o cold. 



2. Process by the Evaporating Battery, (Jmtterie 

 evaporatoire.) 



The battery consists of seven boilers, all of the 

 same size, four boilers forming the first surface, 

 No. 1, two on the second line placed below the 

 first, so situated as to receive their charge bv the 

 simple movement of the ra])e and pulley. They 

 are called No. 2 ; then a little lower stands No. 3, 

 or the darifying boiler, for it also serves for this 

 purpose. 



In beginning to work, the four boilers (No. 1) 

 are first charged with the juice furnished by the 

 defecation. Each of them should have 28| gal- 

 lons (125 litres; making 114 gallons (500 lures) 

 for the four, and which absorb the juice furnished 

 by one defecmtion boiler. The fire is then lighted, 

 the albumen added, if necessary, and the surface 

 skimmed. While these four boilers are in a state 

 of ebullition, the two boilers. No. 2, are charged 

 with water, in order that fire may be ready in the 

 furnace, and when the boilers. No. 1, have under- 

 gone their half-hours ebullition, the water is dis- 

 charged from those of No. 2 into No. 3, and they 

 are charged with the juice of No. 1, which latter 

 are instantly filled with a fresh charge from the 

 defecating boiler. Fire is then put under No. 3, 

 and half an hour after the operation about to be 

 explained, No. 3 is emptied of the water it con- 

 tained, and into it is poured the syrup from the two 

 boilers. No. 2. These again will in their turn be 

 recharged with syrup from the boilers. No. 1, 

 which latter will have a new charge, and so on 

 eonlinually. These operations of charging and 



that quantity in the second. 



If the smallness of the apparatus be considered 

 in reference to the magnitude of the labor per- 

 formed, it will exhibit a striking example of the 

 advantages of a cnntiniied work, which certainly 

 allows of greater results than can be obtained by 

 any other method. 



it may be objected on this point, that the ap- 

 paratus which has been described is fitted only to 

 a large undertaking, and would not do for instance 

 for a small building where not more than a million 

 of kilogrammes (985 tons) are required to be 

 worked up in lour months ; this is true enough, 

 but the system is not less applicable to this last 

 case. It is only necessary to dmiinish the number 

 of the utensils. Thus, instead of four pans, No. 

 1, use two, and so on in proportion, by which 

 about half the quantity can be obtained that has 

 been stated in the first instance, and this may ac- 

 cord very well with a small establishment. In 

 fact there are many of these which do not work 

 above 5 or 6000 litres, (1150 or 1500 tons.) Below 

 this it could not well be reduced, because then the 

 pan No. 3 would be too small to be used with 

 eflect, and would render the clarification very 

 tedious and difficult. 



CHAP. VII. 



Of the Clarification of the Syrup. 



Clarification is intended to separate the juice 

 concentrated nearly to 30° from the substances 

 which it holds in suspension, and to carry off by 

 certain agents the coloring and other extraneous 

 matters fbrtned during the concentration process, 

 and which would otherwise affect the quality of 

 the sugar. Clarification is obviously then an im- 

 portant part of the process of sugar making, and 

 may be divided into two distinct operations, the 

 one chemical, whose object is effected by clarify- 

 ing agents, such as animal charcoal, albumen, 

 &c., and the other, mechanical, intended to sepa- 

 rate from the syrup the carboa and the solid sub- 

 stances collected by the albumen. This last opera- 

 tion, which may be performed by precipitation, or 

 better still perhaps by filtration, will, from its im- 

 portance, form the subject of a particular chapter. 

 It will be distinguished from clarification, properly 

 60 called, which term will be applied solely to the 



