MACHINERY AND MANUFACTURE 197 



of each grade of rubber and should be constantly referred 

 to. The great effort should be to have as small a proportion 

 as possible of what might have been first-grade rubber dis- 

 qualified on account of discolouring or spots. This is where the 

 greatest leakage is usually perceptible. To have a really high 

 grade of first-latex rubber, discoloured sheets should be kept 

 apart, or the standard of the whole lot will be degraded. The 

 percentage of first-latex rubber has been claimed to be as high as 



FIG. 54. Washing and Creping Mill, Large Angle Frame 

 (Bertrams Limited). 



from 75 to 80 per cent, on certain large, well-managed estates 

 with well-equipped factories. This is indeed an excellent 

 showing. In the case of the majority of estates it will be ad- 

 mitted that what is sent to the market as first-latex rubber is 

 far from uniform. Out of fifteen cases there may be five 

 which fetch for example 45. 4jd. per lb., five which realize 

 43. 3d., and the remaining five 45. ijd. If all the cases had 

 obtained the top price the total sum secured by the company 

 would have been much increased. Uniformity in appearance 

 and in quality is very essential. It is really then with the 

 first-latex rubber that the great difficulties are experienced in 



