Ua^cU h im-i THE TROi^iCAL AGRICOLTUKIST. 



S9^ 



sists iu digging a drain, generally 2 feet wide by 1 

 foot deep, at right angles to.the ordinary field drains. 

 Some planters prefer 1 foot 6 inches by 1 foot 6 inches, 

 but this is a matter of opinion, and the quality of 

 the soil has to be considered : the earth which comes 

 out of the drill is used for covering over the trash, 

 which is allowed to rot under it. Should a field not 

 require drilling, then as a rule the bank is ploughed 

 as in plant canes, and the operation of burying trash 

 on the other bank is usually carried out : this con- 

 sists of turning in the trash with the fork or shovel. 

 I may mention that all our ploughing is done with 

 a four-pronged agricultural fork. The trash is com- 

 pletely buried, and allowed to rot. After whatever 

 delving work has been done, weeding and moulding 

 and weeding and trashing are carried on as in plant 

 canes. In 2nd ratoons very similar work is done, only 

 the trash is buried on the other bank to what it was 

 last year, or the other bank is dri'kd; but, like 

 everything else I know of in agriculture, no hard- 

 and-fast rule can be laid down — so much depends on 

 the soil and climatic influence, and in a tropical country 

 with extremes of wet and heat, it is especially so. 

 AVe will now go back to the ripe cane field des- 

 cribed as plants. We will imagine the arrow, or 

 flower, of the cane blown. The cane cutter uses a 

 sharp cutlass, or long knife, 20 to 22 inches long, 

 cutting the cane as close to the ground as possible, 

 with a clean cut, catches the cane by the middle, 

 strikes off the upper leaves, which make the band 

 mentioned when speaking of relieving, and with a 

 .second cut knocks off the top or plant. If the cine is too 

 long the cane is then cut into two or three pieces, 

 and put in bundles on the bank : these bundles are 

 carried out to the cross-navigation trenches, or to the 

 middle walk. Here they are picked up by the punt 

 loaders, and put into punts. ThcNO punts are large 

 flat-bottomed barges, 24 feet long by 8 feet wide and 

 3 feet deep, and, when full, contain about 3k tons 

 of cane, and are hauled by mules to the mill dock, 

 to be dealt with in the factory. The foregoing does 

 not pretend to be more than a general outline of 

 cane cultivation in Demerara. Like everything in agri- 

 culture, opinions differ as to the best methods to em- 

 ploy to obtain the best results, and each may be right, 

 as the position of estates, condition of soil, and effect 

 of weather all have to be taken into consideration ; 

 but I venture to think that many agriculturists in 

 England would be astonished to see the knowledge, 

 care, and attention shown by the leading planters in 

 British Guiana. 



Manufacture. — The canes, once in the mill dock — 

 and thiey are brought there as quickly as pos- 

 sible after cutting — are brought alongside the cane 

 carrier, which consists of two endless bands joined 

 together by cross-pieces of wood to form a table 

 • on whicli the canes rest, and are thus conveyed to the 

 mill. The mills used by us are generally 3-roller 

 mills, and vary in size from 5 feet by 24 inches to 

 6 feet 6 inches by 4B inches and the crushing varies, 

 of course, considerably ou different estates, and also 

 according to the quality of cane which is being 

 crushed, but I do not think more than 65 per cent 

 is usually extracted. On some estates double crushing 

 hae been restored to==-that is pa.ssing the canes through 

 a second three-roller mill; and Mr. Kussell's patent 

 of maceration has also its strong advocates. This latter 

 consists of passing the megass or crushed cane from 

 the first mill through an iron chamber 30 feet long, 

 the megass resting on an endless band of wire web : 

 during its passage through, steam and hot water is 

 turned ou, and the megass absorbs as much as pos- 

 sible or whatever proportion is desired ; it is then de- 

 livered into a second mill and re-pressed, of course 

 the juice being of poorer quality than from first mill. 

 By this method it is claimed as much as 77 per cent 

 of original juice has been extracted. A five-roller 

 mill, by McOnie, has recently been put up in the 

 Colony, and the extraction hitherto recorded has been 

 about 72 per cent, but it was during a season when 

 canes contained a large percentage of woody fibre, 

 and better results are expected. A large portion of 

 (1)6 aill^ ftr« oow fitted Jvitb bydraulic pow«r, wJjicJj j 



enables the pla.itoi- to set his rolls as close as he 

 likes, and to put ou any pressure he may think de- 

 sirable, and is a very great improvement ou tho old 

 set screw, as, no matter what the feed is, an equal 

 pressure is given to one cane as to a hundred, and. 

 thus a loss occasioned by an unjust or careless feed 

 is avoided. The canes having been crushed, the megass 

 passes away on a carrier, either to be burnt directly 

 under the boilers, or is conveyed by trucks to the 

 megass house, or logie, and there allowed to dry until 

 fit for fuel. 



The juice is first strained, then passed through a 

 chamber where it is impregnated with sulphurous acid 

 gas, which both bleaches and assists to coagulate some 

 of the vegetable matter. It is then pumped into 

 clarifiers, and milk of lime is added until nearly the 

 neutral point is arrived at, a slight acid reaction with 

 litmus paper being generally the point aimed at. 

 Heat i« turned ou whilst the clarifler is being filled, 

 and the temperature of the juice raised 190 ^ to 200® 

 F. When this point is reached the vegetable im- 

 purities have risen to the surface in forin of a thick 

 scum : this is carefully removed, and the dear liquor, 

 which should bd bright amber colour, is let down on 

 to an open battery or into a triple effet which is 

 gradually superseding and will in the future entirely 

 take the place of the former ; but whatever method 

 is used the liquor is concentrated to the density 

 required. 



If the open battery or cropper wall, as it is called, 

 is used, the liquor is passed from one trench to another 

 as quickly as is consistent with the cleaning of 

 the liquor, as, as the density increases, scum rises on 

 the surface and has to be carefully brushed or skimmed 

 off until it has had all the impurities removed ; it 

 is then gravitated, or pumped by a Monte-jus, into 

 receivers, ready for crystallising in vacuum pan. Should 

 the triple effet have been adopted the liquor from 

 the clarifiers is run into open pans, or defecators, 

 where it is quickly brought to the boiling point, and, 

 as on the copper wall, the scum as it rises is re- 

 moved; but concentration is not aimed at, and the 

 liquor is run quickly into the triple effet, where the 

 density is raised as required, and from there passed 

 to the vacuum pan. Another method adopted when 

 using the triple effet is to pass the liquor from the 

 clarifiers straight into tripple effet, and when it is 

 concentrated to run the syrup through bag filters 

 to remove the impurities. Both methods have their 

 advocates. 



The syrup once in the vacuum pan is boiled in vacuo, 

 as the name implies, at a low temperature, and gradually, 

 grain is formed. More syrup is added until the pan is full 

 of crystallised sugar ; the pan is then struck out, the 

 mass of hot sugar, with that portion of syrup not 

 crystallised, or molasses, forming what is called the 

 massecuite. This is either allowed to cool or is taken 

 to the centrifugiil machines. These machines consist 

 of an inner case with sides of fine woven brass wire, 

 or finely perforated copper, and an outer case of gua- 

 metal; the inner basket is suspended from above on 

 a spindle, which is made to revolve from 1,100 to 

 1,200 revolutions a minute. The centrifugal force thus 

 set up, forces all the molasses and moisture from the 

 massecuite into the outer easing, leaving the dry 

 crystallised sugar on tho 'inside of the basket. Thia 

 is then taken out through an opening in the basket, and 

 carried to sugar s*ore, ready for packing into whatever 

 packages it is considered most desirable. 



We must go back a little in the process of manu- 

 facture, to where the scum is removed from the clari. 

 fierg, and from the copper wall. This is by no means 

 wasted, but is received into tanks and brought to .the 

 boiling point: it is then allowed to gravitate through 

 bag filters or is forced through filter presses of the 

 Reaumur or Kroogs type, the clear liquor being either 

 drawn straight into vacuum pans or used to mix 

 with the molasses from the centrifugals to make a 

 second quality of sugar. All the sugar which it pays 

 to extract from the molasses having been taken out, 

 the refuse is sent away to the distillery for making 

 rum. This is briefly, and within the limit of tho time 

 allpted to me, a description of sugar cultivating Aa4 



'Jo 



