Vol. XVIII. No. 460. 



THE AGRICULTURAL NEWS. 



391 



Fibre in canes = 



REPORT ON TWO WEST INDIAN SUGAR 



FACTORIES, 1919. 



At the instance of the Directors of Gunthorpes Factory, 

 Antigua, and Basseterre Factory, St. Kitts, the results of the 

 working of these central factories for the past season have 

 been furnished to the Impe.ial Commissioner of Agriculture 

 for the West Indies. The following information extracted 

 from these results will be of interest to those concerned with 

 the manufacture of sugar in the West Indies and elsewhere. 



In order to strengthen the interest of the figures, the 

 corresponding results obtained in Java in 191S are given, as 

 far as possible, for purposes of c.nnparison. These have 

 been obtained from the Lvernational Sugui- Journal for 

 August 1919. p. 386. 



Gunthorpas Factory crushed 90,186 tons ofcanefrom 

 which 0.739 tons of sugar were made. Basseterre Factory 

 crushed ^1 078 tons of caue giving S,8U tons of sugar. This 

 works out approximately at 9 tons of cane to the ton of sugar 

 in th-e case of the Antigua and St. Kitts fact'^ries. During the 

 previous season, namely 1918, the figures for Antigua and 

 St. Kitts were, resyectively, 8-.S tons and 8'5 tons of cane 

 per ton of sugar. 



The main features of ttie factories' work may be gather- 

 ed from the following table: — 



St. Kitts Java. 



81,078 — 



76,501 — 



62,131 — 



76-63 — 



Antigua. 



Uanes crushed, tons 90,886 



Juice diluted, tons 87,789 



.Juice undiluted, tons 65,539 



Juice expressed per 100 cane 72-69 

 Juice expressed per 100 parts in 



cane. Or sucrose extracted per 

 1 00 parts of sucrose in cane 9 2 • 10 



Sucros2 in juice, tons 10,251 



Commercial sugar made, tons y,/39 



Purity diluted juice 83-06 



Sucro.-e in 100 cane 12-30 



Fibre in 100 cane Ib't.^ 



Sucrose in 100 megass 2 7/ 



Juice in megass per 100 fibre 3o-b7 



.Tuice lost per 100 cane 5-9/ 

 llecovery commercial sug r 



per 1>00 sucrose in juice 91-9 

 Com.i:ercial sugar made per 



100 sucrose in cane »* ■•>o 

 Sucrose in above per 100 



sucrose in cane »4: 4- 

 Tons cane per ton commer 



cial sugar ^ -^ 



Polarization sugar made 9t> " ' 

 Molasses Imperial gallons 



(approximately) 365.^00 



Molasses per ton of sugar ^ ' ^ 



"Filter cake, tons i-*" 



Sucrose per 100 filter cake 4-88 



Fibre Content ov raE Cane. . 



93-89 92-1 



9,221 — 



8,814 — 



8400 86-5 



12-11 13-63 



U-36 12-99 



2-55 4-34 



34-74 — 



4-99 — 



91-81 89-16 



86-20 — 



86-25 82-61 



9,198 - 



96-05 — 



380,000 — 



43-0 — 



893 — 



5-4 i 4-36 



(100 - crushing) x 100 

 128 -^ juice per 100 of fibre io megass. 



referred to in the iVest Indian Bulletin, Vol. XVI, p. 96. 



This formula is probably reasonably accurate, but to 

 afibrd correct results, it is necessary that the crushing, or 

 percentage of juice obtained from the canes shall be 

 accurately known. At Antigua and St. Kitts the quantity 

 of true juice ia calculated from the diluted juice on the 

 assumption that, while the purity of the juice obtaine.l from 

 the successive crushing of the train of multiple rollers falls 

 off as one proceeds from one set of rollers to another, the 

 total solids will not very appreciably diminish, the additional 

 impurities extracted compensating to a large extent for the 

 diminished sucrose, so that the quantity of true juice could 

 be calculated from the diluted juice by assuming that this 

 juice has the same specific gravity as the undiluted juice 

 obtained from the first mill. This is perhaps somewhat near 

 the truth when 6- or 8-roller mills are under considera- 

 tion, but a new aspect of affairs is introduced when a train 

 of fourteen rollers, exerting their utmost pressure is employed, 

 as is the case at the factories referred to. 



Recent investigation has led to the conclusion that the 

 quantity of undiluted juice so calculated is too low, in the 

 proportion of about 100:103. This underestimate of the 

 amount of juice, that is to say, an underestimate of the 

 crushing, introduces an inaccuracy in the use of the formula 

 by wliich the fibre content of the cane has been calculated. 

 It is open to us to inttoduce the correction by multiplying 

 the crushing by the factor 103. This has been done, when 

 the fibre in the canes at Antigua in the year under review 

 works outat 1517, instead of 16-67 per cent., and at St. Kitta 

 12 95 instead of 14-36 per cent 



In this connexion it ia interesting to note that abnormal- 

 ly high fibre contents in the canes begin to be reported in 

 1912, when the 14-roller mill at Gunthropes was first 

 used ' with full efficiency ; it was actually in operation io 

 1911, but the work done by it in that year was no more 

 efficient than that of the 8-roller mill previously in use.* 



The fibre contents of the cane of the crops from 1912 

 to 1919 inclusive, are shown in their corrected and uncorrect- 

 ed form, together with the uncorrected fibre contents for the 

 earlier years. 



Uncorrected, as published. Uncorrected up to 1913 



15 1 

 15-2 

 151 

 15-2 

 156 

 15-9 

 15-8 

 Corrected for 

 14 roller mills. 

 16-4 

 16-5 

 15-3 

 15 6 

 149 

 IC-l 

 14-7 

 15-2 



♦Reviews of the work of the Aiit.sjua snd -^t KitUM centriJ 

 factories for the seasons l!n8. li»17 •'-' If"!*; "'"I;': f;"'"!['° 

 the4griou!/w«/ A'^.a.. Vol. XVll.^,. i;76 ^ ul. VVI at ,.. .tofi^ 

 Ldvlil XV. at p. :!.-,.;. r..pect.veh. />'''^; ™^«'-^,/''.g* 

 work of theee f;uloru-s «,U1k- fouud lu \ ol. \VII. p. IBl, 

 Vol. W'\. pp. «•■:»'"' I-'"- ■""' 'n^"'- ^^ • I' '"■ 



