494 



The Supplement to the Tropical Agriculturist 



years' residence in Portuguese colonies pre- 

 scribed by the said law as a condition to privi- 

 lege, have established their claims, and com- 

 bined their lots of 10,000 hectares (24,600 acres) 

 to each individual, in large tracts of from 40,000 

 hectares (98,400 acres) to 100,000 hectares 

 (246,000 acres) m extent. The rubber industry 

 in Portuguese East Africa is not for the money- 

 less settler, however industrious. It offers big 

 returns to the capitalist, by reason of the fact 

 that he can work on a large scale. A conces- 

 sionaire of say 50,000 hectares (123,000 acres) 

 must split up his lands into five or six districts. 

 Each district has a collecting station and a 

 store, for the native had little idea of cash. 

 When he has worked he must be paid in goods. 



With the installation of machinery the semi- 

 skilled labour of the native becomes less and 

 less necessary. In a well-equipped concern his 

 share in the production of rubber will be sum- 

 med up in the simple work of gathering the 

 bark of roots and vine. This can be done equally 

 well by African or coolie. During 1910, rubber 

 to the value of £75,000 was exported from the 

 province of Mozambique, and this dropped to 

 £42,500 in 1911. The great decrease in this im- 

 portant item can be traced to two causes— the 

 break of the iubber boom and consequent col- 

 lapse in prices, and the disturbed conditions 

 which forced a duly organised rubber concern 

 in the province to suspend operations during six 

 months. The break in prices is by far the more 

 important factor, — Royal Society of Arts Journal, 

 Nov. 15. 



RUBBER COAGULATION : MICHiE- 

 GOLLEDGE PROCESS. 



From a succession of experiments conducted 

 over a considerable period, it has been found 

 that to obtain the best coagulated rubber of 

 good quality and even colour from a number of 

 separate estates or divisions, where the latex is 

 coagulated at different points, it is necessary 

 that ooagulation should be carried but on uni- 

 form lines. 



A standard quantity of water should be added 

 to the latex and a standard quantity of acid used 

 in the coagulation. 



To ascertain the proportions required proceed 

 as follows : — 



For a trial coagulation take say I gallon of the 

 bulk and use the same quantity of acid and 

 water as on the previous day and keep a careful 

 account of the bulk (Latex -t-the added water). 



Coagulation being complete, weigh the result 

 ia rubber, which after deducting for wet should 



be equal to one pound dry rubber per gallon of 

 the liquid. 



Should the result be less than this, reduce the 

 water in subsequent lots (or charges) sufficiently 

 to obtain the desired result. 



Ten to thirteen drachms of one of the Glacial 

 Acetic Acid to 6 of water per gallon of the bulk 

 liquid (added water and latex) to be coagulated, 

 will be sufficient to bring about complete coagu- 

 lation, and, as stated above, an even colour may 

 be obtained. 



[The above explains itself and at a time when 

 complaints of the unevenness of plantation 

 Rubber is so very acute may possibly be of some 

 assistance to those who are in difficulties. 



To make an even break of rubber the latex 

 should be standardised and this applies to rub- 

 ber in any form— crepe, sheet, etc. The pro- 

 portions given in above give the best results for 

 practical commercial purposes. 



If a very light amber is sought for the quantity 

 of rubber, per gallon, may be slightly reduced. 

 —Nov. 19th, 1912.] 



Coagulation may be timed by a five minute 

 glass and the whole process made mechanical 

 from start to finish. 



As soon as the sand has run out in the time 

 glass dip into the coagulator without stopping 

 the machine and remove the sponge, the balance 

 if not ready, may be left a minute or so longer 

 till water is clear. The time given above is a 

 fair average but on some days less time is re- 

 quired than others. 



The time taken in coagulating the first charge 

 should be noted and be worked to for all suc- 

 ceeding charges for that day, 



Careful attention should be paid to the speed 

 of the machine — Don't drive too fast, Maximum 

 180 R. (30 R. of driving crank). 



We are indebted to Mr G H Golledge for the 

 following hints on his invention : — 



The best distance apart to set the rolls of the 

 Golledge hand holder is 3-64ths. If more than 

 one set of rolls are used the rollers should be 

 set to a gauge to ensure the rubber being of 

 equal thickness. Once set, the rollers need not 

 be altered. 



It is necessary to express as much water as 

 possible without closing the pores. To effect 

 this the rollers are so set by the makers that 

 they cannot actually touch. 



The back screws (those with the springs]) 

 should be screwed up, by hand, as tight as 

 possible (no force should be used) and the soft 

 awiet to Iti44li9 *A'i '■• • •-. : > - .'•.••i#.;;woj 



