182 THE DEVELOPMENT OF RAW COTTON 



on the other pan. The primary rider is so graduated 

 that the position of the secondary rider upon it shows 

 the percentage of the second weighing to the first weigh- 

 ing, and thus there is only one figure to write down 

 namely, the ginning out-turn as desired. A simpler form 

 with one rider operates for a fixed weight of seed-cotton 

 only. 



Seed Weight. Speed and accuracy in determining the 

 average weight of the seed in a sample are best obtained 

 by weighing out 10 grammes of seed, and subsequently 

 counting them. 



It would appear quicker to count a hundred, weigh 

 them, and obtain the mean weight of one seed by shifting 

 the decimal point. Actually, however, the time occupied 

 in weighing with loose weights is much more than in weigh- 

 ing out seed to a fixed weight and then using the slide- 

 rule. Ten grammes is a useful size of sample. 



Lint Length. Throughout the author's work on cotton 

 this important feature has been determined by measure- 

 ments made on the seed, and not by " pulling " the lint. 

 The disadvantage of so doing is that the measurements do 

 not coincide with the length of the pulled lint, as the 

 grader, spinner, and trade, express it, and, moreover, seed- 

 cotton must be at hand to measure. 



The advantages far outweigh these disadvantages, as 

 the method is far more accurate, and the conventional 

 statement can always be obtained by the addition of a 

 number which is constant for any given strain. Thus 

 33 millimetres " combed " length is 40 millimetres 

 ' pulled " length. Many of the uncertainties which have 



