■Vol. XII. Xo. 299. 



THE AGRICULTURAL NEWS. 



327 



AGRICULTURAL ENGINEERING. 



MECHANICAL EXTRACTION OF RUBBER. 



About two months ago, the lion. W. L. Thornton of 

 Tobago wrote to this Ottice for further information in regard 

 to the rubber-extracting tnachine known as 'Valour', a note on 

 which appeared in the A;/riciiltural ^''eifs for .fuly .">, 1913. 

 Mr. Thornton suggested that the machine might be of use 

 in conne-xion with Castilloa. The matter was followed up 

 immediately, and we are now in receipt of fuller information, 

 forwarded from Paris, from the Agency of the Valour Rubl>er 

 Extracting Machine, Ltd, whose Head Office is at 31, 

 Copthall Avenue, London, E (". 



KINDS OF RUBBEK IXTKACTED. 



So far, the machine — which will be described later in 

 detail — has been employed chiefly for the extraction of root 

 rubber {Landolphia spp.) and rubber from Maniroba 

 (Manihot spp.). It is stated by Professor Jumelle of 

 Marseilles in le Caoutchouc et la Gulta Percha (December 15, 

 1912) that the machine might be used in the case of 

 Funtumia trees also. No details, however, are given. 

 There can be no doubt that the method is best suited to the 

 extraction of Landolphia, because in the rhizomes of these 

 plants, the latex exists in a coagulated form and merely 

 requires separation. In other words, tapping is imposs- 

 ilile. It may lie noted, in continuation of this point, 

 that Landolphia rubber extraction is one of the main 

 industries of East Africa. In his book, Mozambique: 

 Its Agricultural Development, Mr. It. N. Lyne (Director of 

 Agriculture, Ceylon) says: T am convinced that without 

 machinery, root rubber cannot be profitably worked.' 



Although the usefulness of the machine for root 

 rubber can be regarded as established, the point of 

 immediate interest in the West Indies is — Can it be econo- 

 mically employed in any way for Castilloa elastim and 

 for Jequiii Manicoba {Manihot didiotomaf. This latter 

 species appears to lie well adapted for growth in the drier 

 islands, and considerable areas of Castilloa are already 

 established in Trinidad and Tobago, and to a less extent in 

 Dominica and firenada. The machine economises labour, 

 and Castilloa yields lii/ tapping are low. The answer to the 

 above question may best be preceded by a short account of 

 what the machine has been found capable of doing. 



WOEKING OF THE MACHINE. 



Each machine is composed of a large cylinder, the 

 sides of which are perforated. It is mounted horizontally 

 on iron bearings and revolves at the rate of forty five 

 revolutions a minute. Inside the cylinder are five iron 

 rollers, each weighing 37-5 R,, which are free, so that when 

 the machine is put in motion, these continually come into 

 contact with, and completely pulverize, the bark which has 

 previously been introduced. Water is passed in through 

 a pipe. This together with all the debris leaves the cylinder 

 through the perforations, and after an hour or so nothing 

 remains within the cylinder but pure rubber. 



Each machine requires 3 h.p. to drive it. (Jenerally 



it is economical to employ a battery of six machines, and 



a 24 h.p. engine. Each cylinder is aV)le to receive 70-5 ft). 



•of bark. A battery of six will .leal with about 400 R. 



. in an hour and a half. 



SPECIAL ADVANTAGES. 



It should be noted here that the arrangement can work 

 without water— a very important feature under certain 

 circumstances. Other advantages are that the machines, 

 can be operated either by motor power or by hand, and that 

 no part of the machine is too heavy for a man to carry. 



COST. 



The installation of a battery of six machines witli 

 a 24 h. p. engine, and all accessories, at a point not mora 

 than .50 kilometers from the nearest railway station or 

 shipping port, costs 50,000 francs (about £1,960). The 

 total working expenses are put down at 410 francs (about 

 £16) per day, and under average conditions this should 

 leave a net profit of 790 francs (about £31) per day. These 

 figures refer to large exploitations of root rubber. In tha 

 West Indies a single cylinder worked by hand power 

 would probably only come within the bounds of practical 

 considerations. 



THE MACHINE AND CASTILLOA E.\TEACTI0N. 



O. F. Cook, in Bulletin No. 49 of the United States De- 

 partment of Agriculture,discusses the possibilities of extracting 

 latex from the temporary branches and the unripe fruit of 

 of Castilloa. It is a point worth bearing in mind, that the 

 machine under consideration might serve a useful purpose ia 

 this respect. Of course, it must be remembered that the 

 machine is more in the nature of a separator than anything 

 else, and in this respect it might be useful for cleaning scrap 

 rubber that has coagulated on the trees. The point may be 

 raised as to why it is that Castilloa with continuous tapping 

 gives lower yields. The question does not seem to have 

 been raised as to whether it may not be due in part to the 

 coagulation of the latex in the bark. If this were so, the 

 possibility of barking Castilloa would be worthy of consid- 

 eration, and then the question of the employment of the 

 rubber- extracting machine would be a very vital one.* 



Alcohol as a Motor Fuel.— If it could be defin- 

 itely decided whether motors for agricultural work can be 

 con.structed to use alcohol instead of petrol as a fuel, it ia 

 believed that the question of employing alcohol as a motor 

 fuel would be of very great agricultural importance. 

 According to Th Times (July 22, 1913) Mr. E. G. Evans, 

 representing the South African Agricultural Union has 

 maintained that, under the foregoing conditions, if only 

 motor fuel could be produced from a growing product such 

 as maize, the benefits would be very great. It is sug- 

 gested in continuation of this view, that engineers should 

 direct their attention immediately to the construction of 

 motors suited for use with alcohol. 



The whole subject is of much interest, in view of the 

 great importance which is now being attached to motor 

 cultivation in places where the soil is heavy, or where labour 

 is scarce, or where the tsetse fly will not allow cattle to 

 work. It may be added that the subject is of particular 

 significance when considered in conjunction with the view.s 

 put forward in the editorial of this issue, in regard to the 

 manufacture of alcohol during the fermentation of cacao. 



♦It would be useful to have the views of Castilloa crowei-« 

 on this subject— [E<1. A.N.] 



