8 BULLETIN 591, U. S. DEPARTMENT OF AGRICULTURE. 
the manufactured product, especially the tensile strength, can not be 
recognized by the present inexact method of judging the quality of 
raw cotton. Irregularities in the manufactured product are mini- 
mized by adequate methods of mixing the cotton for manufacturing. 
SPINNING TESTS AT TEXTILE SCHOOL. 
It was deemed advisable to make tests under different conditions; 
therefore, tests were made both in commercial mills and in textile 
schools. 
F IC >. 4.— The tensile strength of 22's warp yarn, made with 4.74 twist constant from the different grades of 
Eastern Upland and Western Upland cotton. (Mill tests.) 
Fifty pounds from each of the 109 bales tested in the mill were sent 
to the textile department of the North Carolina State College of Agri- 
culture and Engineering, West Raleigh, N. C. In conducting these 
tests the cotton originating from each of the different zones shown 
in figure 1 was tested separately. The mechanical conditions were 
made to duplicate as nearly as possible the conditions prevailing 
during the mill test. (See Table I.) In the textile-school tests the 
cotton passed through the following waste-cleaning machines: 
Opener and finisher, pickers, and cards. 
