6oo 



THE TROPICAL AGmcVLTVmST, [March i, i88^. 



manufacturing as carried out in Demerara. It may 

 differ in details in the practice adopted on different 

 estates, but it contains the general principles usually 

 employed. 



It has been said by people in England, and reported in 

 the newspapers, that the reason why we do not succeed 

 with sugar in the West Indies is that we do not employ the 

 best means to extract the sugar from the cane, that our 

 machinery is antiquated and not powerful enough — 

 in fact, that we have stood still. Such, at all events, 

 cannot be said of the planters of Demerara, unless, 

 indeed, the English engineers have also stood still, as 

 machinery of the newest design, without reference 

 to cost, is, and has been for many years past, impor- 

 ted into the Colony from the best firms in England 

 and America, and all that the planters and their 

 agents can do is done to keep pace with the times. 

 That this has been recognised is fully borne out by 

 the constant visits of agents of engineering firms 

 from Englai d and the continental nations, and the 

 adoption of their inventions, often the reverse of im- 

 provements, that have been palmed off on us. 



I have been gibed at that ive have not yet adop- 

 ted "Diffusion," which, according to some, is to be 

 the panacea of all our troubles. All I can say to 

 that is, the matter is receiving the fullest attention 

 and our leading proprietors will not .«pare their capital 

 when they have before them such figures which will, 

 warrant their destroying their present plant of 

 machinery and in spending so large a sum of money- 

 These have yet to be forthcoming, and it is as much 

 the business of engineers who are com ooted with 

 the sugar trade, and whose business is, according to 

 their own showing, very bad, to try and obtain 

 figures which would justify their making a diffusion 

 plant, and, even if it does one-half that is claimed 

 for it, orders would soon pour in. I will confess to 

 one thing that we were, and still are, deficient in, 

 and that is, employment of trained chemists in our 

 works : it is fast being remedied, and men well train- 

 ed, with a knowledge of sugar manufacturing, can 

 now easily obtain employment with us — not boys 

 from school and laboratory, but those who have made 

 it a study, and will lay themselves out for original 

 observation and research. I can only trust and hope 

 that snch improvements will be made as will enable 

 us to fight with success against the odds of bounty- 

 fed continental sugar, which the Eoglish Government 

 unfairly assists under the taking garb of free trade. 



TJSINE SnOAR. 



The usine .system of sugar production takes its 

 name from the French word " usine," owing to the 

 fact of the system having been first introduced and 

 worked by the French in the Colonies of Martinique 

 and Guadeloupe. The system owes its origin to the 

 late M. Cail, head of the celebrated firm of Paris 

 engineers, Messrs. Oail & Oo. The essential feature 

 of the system is the complete separation of the in- 

 dustry of cane growing from that of sugar manufac- 

 ture; but the success of the system is more to be 

 attributed to the fact that the usines which were 

 established under the auspices of Messrs. Oail & Co. 

 were supplied with the improved machinery which the 

 development of the beet-sugar industry on the conti- 

 nent had brought about. Previous to the adoption 

 tJf the usine systerUj the cultivation and the manufac- 

 ture of the cane had been carried on generally on 

 small estates making from 100 to 500 tons of sugar, 

 the manufacture being of the simplest character. 

 The canes were crushed by mills similar to those 

 still employed, but in a rougb-and ready manner, the 

 extraction of juice being probably at least 10 per 

 cent less than that now obtained, and the evaporation 

 was conducted on what is known as the copper wall, 

 i.e., in open pans with a naked fire underneath. The 

 concentrated cane juice was struck into shallow 

 vessels called coolers, where crystallisation took place : 

 from these coolers the sugar was dug out and placed 

 in hogsheads, in which it remained until the greater 

 part of the molasses was drained out ; the hogsheads 

 were then headed up and ready for shipment. There 

 is no doubt that this process is one which fails to 

 •Stoin as much eu^ar from the jmee a» caa be ob 



tained by more scientific mean-, At the same time,' 

 the process has much to recommend it when it is 

 considered that a very sinill outlay of capital is' 

 requirecl, and that it is so simple that there is no 

 difficulty in working it with the ordinary uneducated 

 black labour of the tropics. — Colonies and India. 



Insects and Frost. — The writer of the interesting 

 Agricultural Notes in the Daily Newsoi Saturday last, 

 referring to the weather, stated that frost was useful 

 in keeping down insects, the larva perishing during 

 prolonged frost. It would be useful to learn from some 

 experienced entomologist how far that assertion is true 

 [not true]. I am disposed to think it belongs to the 

 category of popular errors, or, if not, needs more proof 

 than has yet been given. The previous winter was 

 decidedly a severe one, and we had much intense frost, 

 and yet it will be remembered that rarely have queen 

 or breeder wa>ps been more abundant than they were 

 last spring, although most of them seem to have perished 

 later. Then the writer specially mentions Daddy Long- 

 legs as being more plentiful after a mild winter, and 

 yet I never saw them so abundant as last autumn, 

 indeed, it seemed as if the wasps had for the time 

 been metamorphosed into these comparatively harm- 

 less insects. Is it not really the case, that whilst 

 mild winters keep insects lively and thus exposes them 

 to the attacks of birds, severe winters keep the larva 

 not only quiescent, but also find it deeply buried? 

 Has a severe frost, for instance, any destructive effect 

 upon the eggs of insects deposited on trees or in wall 

 crevices, or even in the soil ? — and equally, does it 

 really destroy comatose larva? Any entomological in- 

 structions to gardeners should make these matters 

 clear. The recent frost, although at times intense,, 

 did not penetrate so deeply into the soil as in some 

 previous years, because of the snow. "With me, just 

 now, insect larva is more in danger of destruction by 

 drowning than by frost. — A. D. — Gardeners' Chronicle, 



Quantity of Water per acre required to Irri- 

 gate Rice. — The Indian. Agriculturist states: — A cor- 

 respondent of one of the mofussil papers settles the 

 question of the quantity of water required to raise » 

 rice crop — a question to which Mr. C. Benson of the 

 Madras Agricultural Dep?rtm"nt drew particular at- 

 tention recently — in the following simple manner: — In 

 your editorial notice of the report of the Madras Agri- 

 cultural Department published in your issue of the 10th 

 instant, you refer to " A suggestion made by Mr. 

 Benson, Agricultural Reporter, that an elaborate 

 series of expriments should be undertaken with the 

 view of ascertaining the proper amount of irrigation 

 required to raise a crop of rice." I beg to state that 

 when I was in the N zam's State between the years 

 1865-71 repairing tanks and cutting channels from 

 rivers for the purpose of feeding these tanks, I found 

 it necessary to ascertain first, before determining the 

 bank sections, &c., what quantity of water the tank 

 would be required to hold in order that it should be 

 capable of irrigating the land under it. To enable me 

 to obt'in some correct and precise inforraHtion for 

 my own daily use, I invariably consulted the zemindar 

 putwari and head ryot of every village I visited prior 

 to commencing with the levelling and survey operations, 

 and arrived at the following couclusions : — From a 

 series of notes and observations I found that it took 

 on an average about 72 days. 



Days days days days days." 

 59 + G7 -I- 90 216 72 



I 



to raise one crop of rice ; and that the land required 

 as much water as would cover it all over to the 

 depth of 1 inch, i. e. 



72 X 1 =72 6 



— = — = 2 yards, 

 13 3 

 So, therefore, to irrigate one acre of land — namely, 

 4,840 square yards-— a tank should hold— 



4,840 X 2=9,680 cubic yardf of water. 



