98 



every shipment. The last is the mo'^-t important of all from the 

 manufacturer's point of view as it saves time and money in 

 experimenting with each shipment, and if he can rely on an estate's 

 output giving the same results regularly he will buy that rubber and 

 pay full value for it. This serves to show that, having found the 

 right methods in the factory, a manager is ill-advised to alter any 

 part of his process, as any change may have a strong bearing on the 

 results given by his rubber under tests and put the buyers off for 

 some considerable time. 



Straining of Latex. 

 The first important part of the making of smoked sheet is the 

 straining of the latex. This should be done through fine gauze, 60 

 mesh, and two sieves should be used — one above the other. The 

 reason for this is that if the sieve gets clogged the cooly in charge 

 invariably rubs the gauze with a piece of rubber till the latex runs 

 freely through, and fine sand and dirt get pushed through with the 

 latex. The lower sieve catches anything of the kind, and no 

 rubbing of the gauze should be allowed on the lower sieve. If this 

 gets clogged it should be replaced by a clean sieve and used on top, 

 the one formerly on top being removed and thoroughly washed to be 

 used again. A suflScient number of spares should be at hand to 

 change continuously. 



Standardization. 

 I dilute with cup washings simultaneously with the straining of 

 the latex, both going together through the two sieves. No water is 

 put in the cups during tapping so that the latex is too rich in itself, 

 and the cup-washings increase the output of sheet by about 2 per 

 cent, without any harm being done, as dirt cannot pass through both 

 sieves. There is probably one gallon of cup- washings to two 

 gallons of pure latex in the mixture, and the out-turn on the total 

 gallonage for the last two years has been 1| lbs. of dry rubber per 

 gallon, variations from month to month being fractional, and 

 dependant on weather conditions. Rain during collection upsets 

 most calculations, and an attempt to preserve uniformity is made 

 during coagulation. In normal weather I can rely on standard latex 

 without the aid of a " Metrolac." Owing to the fact that I have 

 contract tapping at varying rates I have to separate latex from trees 

 over 10 years old from that from young trees. In pan coagulation 

 J of a gallon of water is put into each pan. If rain has fallen during 

 collection this is dispensed with and instead of a gallon of latex and 

 cup-washings being put into each pan the latexometer is brought 

 into the picture and sufficient latex and cup-washings put in to 

 equalize as neai-ly as possible a normal day's size of sheet. I 

 deprecate the use of the " Metrolac " more than is necessary. It 

 means nothing to the ordinary cooly, who, if he has been at the 

 job long enough is a very good judge of the density of latex by 



