Vol. XVI. No. 405. 



THE AGRICULTURAL NEWS. 



351 



•for good results, care must be taken to keep clear around 

 €ach tree a space just sntiicient for its full development. 

 Removal of the shelter will thus be grarlual. Anything 

 approaching overhead shade should be avoided. In appyling 

 the third method, the more shelter in the way of wind- 

 breaks and hedges is provided, the less will be the 

 attention requir. d to maintain the vigour of the trees. 



The conclui-ion drawn from these experiments with 

 regard to natural resistance to scale insect infe.stations are 

 applicable to mature trees but under Dominica conditions 

 these are rarely severely attacked. 



MOTOR TRACTORS. 



In view of the present conditions of agriculture, and 

 siill more perhaps of future conditions when the war is over, 

 the following article taken from Occasional Xoten, No. 2, July 

 1917, published by the Royal Agricultural Society of 

 England, is of interest. The article is written by the Soc 

 iety's Consulting Engineer, Mr. F. S, Courtney. M.I.C.E : — 



'The subject of motor tractors must, at the present 

 "time, seriously occupy the attention of most agriculturists, 

 and under ordinary conditions (when intending purchasers 

 might be considering the selecting of a tractor to meet their 

 requirements) a general description and criticism of such 

 tractors as are in the market might be of a useful guide. . . . 



'Of such tra''tors there is a great variety, and as each 

 one varies very considerably in design, it is evident that 

 • — even with American tractors — there is at present no 

 unanimity of design. 



'In evidence of this one has only to look at their 

 framing, and the disposition and number of their wheels, 

 some being 3-wheeled, while with the 4-wheeled there is an 

 ever differing variety in their disposition, width, and diameter. 



'Then, there are marked differences in the engines and 

 gears; these, however, need not be considered at the moment. 



'I have not the slightest doubt but that the prospective 

 large application of motors to be used immediately in the 

 development of arable land in this country will, within 

 twelve months of their being set to work here, result in 

 a very material modification, certainly with those makers 

 who desire to maintain their footing in the English market. 



'For these reasons I do not think it desirable to go into 

 any criticil examination of tractors in their present form 

 or of their probable modifications. It is much safer to 

 "prophesy after the event" and there is, no doubt, much 

 •which we shall learn by their extended use, and which will 

 clear up some vexed questions. 



'Perhaps the first of these is the weight of the tractor 

 itself. On the one hand, weight is reduced to a minimum 

 80 that a tractor is produced wtighing little over a ton 

 ■with its full complement of oil, etc.; while, on the othtr 

 hand, there are advocates of caterpillar tractors weighing 

 thirteen or fourteen times that weight. How far the distri- 

 bution of weight over a greater area of bearing surface 

 is eflfective can only be definitely decided by a comparison 

 of the crops grown on similar soils, but tilled with machines 

 of varying weight. 



'Apart from the class of tractor referred to above 

 there is the combined tractor plough, which certainly 

 should not be lost sight of. With either a plough or culti- 

 vator the implement is capable of doing a large amount of 

 excellent work, and is especially adapted for irregular-shaped 

 or small fields. In order, however, to get the maximum 

 effect out of such a machine, it would appear e-sential thai. 

 the driver should not have to follow and steer it, but that he 

 ^'hould have a .seat on it, with all the controls brought close 



to his hand, and each capable of easy regulation. In this 

 way he should be able to get nearly double tlie work out of 

 his machine that he would by following it. 



'The task of placing some thousand of tractors on the 

 land within a short period is an immense one, and it wOuld 

 be expecting too much that the organization of the samft 

 should at first be perfect 



'It will be interesting to follow and note the modifi- 

 cations which will, as a consequence, be made in the machines^ 



'The omission of steam cultivation from the above 

 must not be taken to assume that I consider it super.sedeif 

 by the motor tractor; on the other hand, given large field* 

 and sufficient area to plough, no better work can be dona 

 than by steam.' 



ANNATTO DYE. 



Some years ago the Imperial Commissioner of Agricul- 

 ture for the West Indies gave attention to the question of 

 preparing the colouring matter from annatto seeds, and dis- 

 covered a simple process for the purpose. He found thati 

 the colouring matter is easily removed from annatto seeds 

 by washing them in a dilute solution of ammonium hydrate. 

 The solution is strained off from the seeds and evaporated 

 to a thick paste in steam-heated pans, when it yields aa 

 annatto paste of greater brilliancy and colour than that; 

 obtained in the usual way. 



The great simplicity of this proce.«s would permit of its 

 being carried out in places where annatto is growa.'so that tha 

 concentrated paste might be shipped instead of the somewhat- 

 bulky seeds. 



Considering the shortage of dye-stuffs, the Commissioner- 

 brought this matter to the notice of the Colonial Office ia. 

 February this year, suggesting that it might be well to 

 submit the idea to the Inventions Board, as of possible use al;. 

 the present moment. The Department of Scientific and 

 Industrial Research was consulted in the matter, and iti- 

 has intimated that annatto is now chiefly used for colouring- 

 butter and cheese, and only to a very small and unimpor- 

 tant extent in dyeing. 



Annatto is grown hardly anywhere in the West Indies 

 to any extent, except perhaps in .Jamaica, which still pro- 

 duces a small quantity. Should there be any future for 

 this dye, an<l the cultivation of the plant extended, it would 

 be an easy matter in carrying out the process suggested, to 

 treat the annatto seed with ammonia and water in rotating 

 churns, to strain oft' the liquid, and evaporate this to a paste 

 in steam-heated copper pans, so that a factory for the 

 purpose would be a simple affair. The residual seeds might; 

 possibly be used for oil production, and for cattle food. 



A telegram from Amsterdam, printed in T/ie Ti/nes for 

 August 20, 1917, states that the Union of German Sugar 

 Industry has stated to the German Chancellor that the 

 Cnion desires the continuance of the Brussels Conventioa. 

 after the war, on condition that England .shall agree to it. 

 It is pointed out that England during the war has mainly 

 used colonial sugar. It is of importance therefore to the 

 German industry that cane and beet .sugar should be placed 

 on an equality as regards their import into England, so that 

 colonial sugar may not perin,inently exclude beet sugar 

 from the British market. This seems to be either a confes- 

 sion of weakness on the part of the German sugar industry^ 

 or an instance of German insolence. 



