144 THE DEVELOPMENT OF RAW COTTON 



the maximum diameter of the lint has nothing to do 

 necessarily with comparisons of fineness from one kind 

 of cotton to another, as is so frequently stated. 

 On looking through published figures on this 

 subject, one is struck with the way in which data for 

 diameter have been stretched to make them fit the view 

 that diameter and fineness are equivalents. The extreme 

 range of mean fibre diameter in good samples of all com- 

 mercial cottons may be taken as 0-016 millimetre for Sea 

 Island, and 0-025 millimetre for some Indian cottons. 

 The squares of these numbers stand in the ratio of , roughly , 

 2 : 5, and variations of this magnitude in fineness may be 

 found within Egyptian cotton alone, where the diameters 

 are practically constant. If, however, we consider the 

 thickness of the wall of the fibre, which cannot well be 

 measured except by cutting sections, and so obtain 

 figures showing the thickness of the walls, they will 

 follow the gradings for fineness much more closely. 



Thus we reach a definition of fineness as practically 

 equivalent to hair strength. Fineness is partly a matter 

 of cell diameter, but more a matter of wall thickness. 



The statement just made, that a fine lint is weak lint, 

 may at first seem to be a reductio ad absurdum, but it 

 needs further consideration from the grader's point of 

 view. 



Grader's Strength. In the preceding chapter we saw 

 that grader's strength and breaking strain were entirely 

 independent, and that not merely from day to day in the 

 same kind of cotton, but also between different cottons. 

 We also concluded that the grader tested the lint for its 



