Vol. XII. No. 2S8. 



THE AGRICULTL^RAL NEWS. 



147 



science, and in any large educational institution that 

 may, in the near future, be established in the Tropics, 

 the provision of a lecturer who possesses a first hand 

 acquaintance with the organization of the different 

 manufacturing industries dependent on tropical yuo- 

 duce, would be at least one way of helping to bridge 

 the gap that at present separate? the producer of raw 

 material — ^in particular the producer of cotton — from 

 the centres of retail consunijjtitm located in the large 

 cities. 



SUGAR INDUSTRY. 



MULTIPLE MILLS. 



Dr. W. E, Cross has lately contributed to the Lonisinna 

 I'laiiti)- an article entitled Itecent Progress in the Cane- 

 sugar Industry, which is concerned mainly wiih the subject 

 of tlie advantages of multiple milling. It is put forward 

 as practical evidence of suiii>ort, that m-dern high grade 

 Biills are very often found, especially in tro|)icil countries, in 

 factories which are in other respects soniewhat primitive. 

 The advantages, or rather the actual etti i^ncy of multiple 

 milling is indicated in the article referred lo, by the inclu- 

 sion of a table of extraction figures, the result of comparative 

 observations on nine- and six-roHer mills in Jjouisiana. 

 Stated shortly, a nine-roller mill (length ti feet) ground 

 4.3 2 tons of cane per hour with a juice s.xtraction of 791.5, 

 and with a percentage loss of sucrose of 4'27 lb.; whereas 

 the si.x loller mill (length 7 feet) ground only 39 61 tons of 

 cane per hnur, gave a juice extraction of 77 45 per cent., 

 and a percentage loss of sucrose amounting to 502 lb. 



Moreover, it is pointed out that if it be desired to 

 hasten the grinding, Hie nine-roller mill can grind more cane 

 than the other with the same extraction, as the following 

 figures show: six roller mill with crusher, 950 tons per day; 

 nine-roller mill with crusher, 1,214 tons per day; twelve-roller 

 mill with crusher, 1,478 tons per day. Xot only is better 

 extraction obtained but ths mpga=s, by passing through the 

 fourth set of rollers, is dried much rrore thoroughly, and its 

 fuel value, therefore, so much increased, that it produces 

 more than enough extra steam to drive the fourth mill. 



Referring to the reports on multiple milling that have 

 been issued from Java and Hawaii, it is pointed out, first, 

 Huit in the former country during the last five years, the high 

 level of 91 per cent, exti action (juice on juice) has been main- 

 tained, and that the sugar lost in the megass has been stead- 

 ily kept down to a low limit. In Louisiana objections are 

 constantly rai.sed against the use of nine- and twelve roller 

 mills because, it is said, the purity of the Louisiana juice is 

 too low, and the increased extnction would result in 

 a smaller percentage of actually available sugar. The figures 

 of Noel Deerr, hovrever, show this idea to be wrong; for 

 although the last milt juice is of a purity considerably lower 

 than that of the first mill juice, yet the purity of the total 

 (i e. mixed) juice is only very slightly lower. 



As regards the Hawaiian report.".-, e::treinely interesting 

 and valuable new data have arisen from a comparison of the 

 efficiency of a twenty one-roller mill with the twelve and 

 eighteen. It would appear that the larger multiple mill 

 gives nearlj' 1 per cent greater extractio^i, with a dilution of 

 £15 percent, as against 37 7 per cent, extraction in the 



case of the latter kinds. Moreover, the weight of c m- 2rouncI\ 

 per linear fo 't is 9 for the twenty-one roller mill a- ciinpared 

 with 6 2 for the twelve, thus conclusively showing the far' 

 greater capacity of the larger comliination. 



DAMAGE TO SUGAR-CANE BY FIRE. 



The burning of cane either by accident or design has- 

 become so common in certain districts in <,)ueensland tli it it 

 was resolved at the recent conference of the Australian Suijar • 

 Producers' Association in Brisbane to ask the Council to <leal: 

 in an adequate and [irompt manner with the whole matter 

 at their next meeting. 



In the Australian Smjar Journal for March 6, 1913,.. 

 where the subject is referred to at some length, it is stated, 

 that recent analyses have sjown that losses from buming;- 

 occur to the following extent. In the first plac,^ there is 

 a loss in weight which is never less than 4 per cnt. and^. 

 on the average, probably as high as 6 or 7 per cent. Accom- 

 panying this, there is an increase in the percentage of fibres 

 which leads to corresponding difficulties as regards extrac- 

 tion Moreover, the deterioration in the field is more- 

 rapid in the case of burnt canes than in the case of green 

 canes cut and left in the same way Furthermore, an. 

 average interval of three days between burning and. 

 milling causes a minimum average reduction in value of 

 20 per cent. In one experiment, during ten days thwi- 

 following changes were found to have taken place: on the- 

 day of burning the analysis was: Brix., 2419; sucrose, 2236;:: 

 quotient of purity, 92'43; glucose, 41; glucose ratio 1 83;:. 

 per cent, sucrose in cane, 1792. On the tenth day, analysis-. 

 gave the following result: Brix, 2059; sucrose, 14-95;. 

 quotient of purity, 72-61; glucose, 4 17: glucose ratio., 

 27 S9; per cent, sucro.se in cane, 1007. 



It is stated further that practical experience supports* 

 the above figures, since on several estates it is taking fronS' 

 10 to 12 tons of burnt cane to make a ton of sugary 

 whereas of green cane only 7 tons are required. 



A REVERSIBLE BARREL. 



The in\ention d-scribed in the following extract, 

 taken from the Ivtemiational Sugar Journal, for 

 Marcii 19K?, is likely to be of great economic impor- 

 tance in tropical agriculture. It may solve the diffi- 

 culties incident on the shipping of low grade molasses, 

 and may prove to be an extremely profitable factor 

 in ■ thii exportation of lime juice and similar agri- 

 cultural produce: — 



A patent has recently been taken out for what is-- 

 described as a reversible barrel. It consists of two equal- 

 sized conical steel halves bolted together in the middle at 

 a joint consisting of an elastic and chemical proof Dermatine- 

 ring lying in a groove. The principal advantage of this, 

 design is that, in returning empties, the halves can be nested, 

 one in another and so take up far less space. Stetl barrels; 

 for holding 10 cwt. of molas.ses and weighing themselves-. 

 2 cwt each are returned empty to Natal at a freight charge^ 

 of 7s. 6(/. each; nested barrels of the same capacity would, 

 go for 2.S. 6rf. Again, mineral oil barrels which would cost. 

 £1 17s. Gd to return to the United States (the chargB'- 

 being by space), could be replaced by nesting barrels which, 

 travelling by weight would cost 5s. to return empty. There^ 

 are other advantages claimed for this patent barrel, such as 

 the abiliiy to clean and coat the insides. All halves ara- 

 interchangeable, any two will make a barrel, or single halvea- 

 may be used with a cover plate. 



