1 68 RUBBER AND 



simply by external inspection. Both these objections 

 can be overcome by making flat blocks, which should 

 not be more than one or two inches in thickness. Such 

 blocks however are somewhat more troublesome to make 

 than thick ones. 



Scrap Rubber. 



The highest grade of rubber prepared from the 

 strained latex is known as First Latex Rubber. Other 

 grades are prepared from the strainings of the latex, 

 from the scraps of rubber which have dried on the bark 

 of the trees or in the collecting cups, from the shavings 

 of bark removed in paring, and even from the latex 

 which has dried upon the ground beneath the trees. 

 The scrap from small estates is sometimes sold as such, 

 but on large estates the whole of it is turned into crepe 

 of various grades, according to the colour and the 

 amount of impurity remaining after the washing pro- 

 cess. After passing repeatedly through the macerating 

 machines, the greater part of the impurities present are 

 washed away, and the value of the rubber thus produced 

 is only 20 or 30 per cent, less than that of First Latex 

 Crepe. 



Packing. 



The rubber is packed in wooden cases containing 

 generally between I and \\ cwts. It is most important 

 that the inside of the cases should be smoothly planed 

 and perfectly clean, and that no packing material of any 



