4 



BULLETIN 990, U. S. DEPARTMENT OF AGRICULTURE. 



The visible waste discarded by a cleaning machine can be governed 

 by the settings used on that machine. 



The invisible waste can not be governed with any degree of accu- 

 racy, since it depends upon the grade and character of the cotton 

 and the relative humidity at the time the cotton is run. Table 2 

 shows that there was a large invisible loss on the grade of Low 

 Middling on the pickers. This loss is partly accounted for by the 

 low relative humidity and high temperature existing while this grade 

 was being run. (See Table 3.) 



Table 3. — Average temperature and relative humidity in picker and card room. 



Room. 



L.M. 



G.M.Y.T. 



M.Y.T. 



L.M.Y.T.jG.M.Y.S. 



M.Y.S. 



G.M.B.S. 



M.B.S. 



Pickers: 



Average temperature 



Average relative humid- 

 ity 



°F. 

 81 



45 



81 



63 



°F. 

 85 



69 



81 



73 



°F. 

 86 



70 



81 



75 



90 

 60 

 84 

 69 



°F. 



85 



65 

 79 

 68 



°F. 

 79 



62 



81 



64 



°F. 

 77 



65 



80 



71 



°F. 



88 



61 



Cards: 



Average relative humid- 

 ity 



91 

 63 











All grades except G.M.Y.S., M.Y.S., and M.B.S. stood overnight between the pickers and the cards. 



If the total percentages of waste are used as a basis of value the 

 following order is obtained : 



(1) Good Middling Yellow Tinged; (2) Good Middling Yellow 

 Stained; (3) Middling Yellow Tinged; (4) Good Middling Blue 

 Stained; (5) Low Middling; (6) Middling Blue Stained; (7) Mid- 

 dling Yellow Stained; (8) Low Middling Yellow Tinged. 



MOISTURE DETERMINATIONS. 



Samples of each grade of cotton were taken at each machine or 

 process, weighed on a sensitive equal-arm balance, placed in air-tight 

 cans, and shipped to Washington, dried to absolute dryness, and 

 reweighed on equally sensitive balances. The moisture content of 

 each sample was then calculated. The results are shown in Table 4. 



The low humidity conditions noted on the pickers while the Low 

 Middling grade was being run are checked by the moisture content 

 of the samples taken at this process. 



Table 4. — Percentages of moisture 1 in the cotton of the different grades at 

 various points in the cotton-manufacturing processes. 



Sample. 



L.M. 



G.M.Y.T. 



M.Y.T. 



L.M.Y.T. 



G.MY.S. 



M.Y.S. 



G.M.B.S. 



M.B.S. 



Raw cotton from bale breaker 

 Lap from opener-breaker lap- 



Perct. 

 5.59 



4.17 

 4.17 

 5.04 

 6.21 

 8.51 

 6.67 



Per cent. 

 7.47 



8.28 

 8.64 

 8.17 

 7.64 

 6.78 

 6.49 



Per ct. 

 6.55 



7.58 

 7.70 

 6.89 

 7.47 

 6.83 

 5.99 



Per cent. 

 6.78 



6.72 

 6.61 

 6.44 

 6.21 

 6.78 

 7.24 



Per cent. 



7.18 



7.47 

 7.53 

 6.95 

 7.24 

 7.00 

 6.04 



Per ct. 



7.75 



6.95 



7.41 

 6.49 

 7.18 

 6.38 

 6.38 



Per cent. 

 6.44 



6.67 

 6.49 

 6.38 

 6.61 

 5.26 

 5.54 



Per ct. 

 6.72 



6.67 



Lap from finisher picker 



5.88 

 5.71 



Sliver from finisher drawing. . 



5.93 

 5.76 

 5.76 







1 Percentages expressed as "regain." 



