SPINNING TESTS OF UPLAND LONG-STAPLE COTTONS. 15 
bale in favor of the Carolina staple cottons as against the Delta, while 
on the 23 to 25 per cent setting the average of the Carolina cotton 
shown in the last column in Table IX is $G.95, and that of the Delta 
$7.85, a difference of 90 cents per bale, in favor of the Delta on the 
wider setting. 
The grade of the samples being tested does not appreciably affect 
the quantity of the comber waste, as is shown by comparing Durango 
and Lewis, both of which are good middling, but which show a dif- 
ference of 8.28 per cent in comber waste on the 23 to 25 per cent 
setting. 
ACCURACY OF THE MACHINE WORK. 
The following mathematical formula? show that the variations in 
percentages between the 13 to 15 per cent and 23 to 25 per cent set- 
tings on the bales showing highest and lowest waste are consistent 
with the mechanical changes involved: 
25-^-15=1.66, the ratio between the two settings. 
21.81-^13.07=1.668, the ratio between the two percentages actually 
obtained on the Webber No. 1. 
12.15-^8.08=1.504, the ratio between the two percentages actually 
obtained on the Lewis cotton. 
The mechanical construction of the comber is such that all fibers 
up to any desired length are taken out, so that these results repre- 
sent fairly the inherent value of each bale tested, when used 
for fabrics which require combed yarns. If later tests substantiate 
the findings of this report, namely, that these bales are representative 
of inherent differences in the varieties represented, as there is every 
reason to assume, the great importance to the spinner of knowledge 
concerning the varieties of cotton purchased for his mills will be 
fully demonstrated. It is not safe to assume, however, that the same 
differences will be found between representative bales of these vari- 
eties when the latter are grown under radically different climatic 
conditions. In other words, uniformity may prove to be a much 
more constant characteristic of some varieties than of others. 
FACTORS INFLUENCING WASTE. 
There are a multitude of factors which influence the percentage of 
waste in such tests as those here discussed. If cotton is picked and 
ginned while damp, or is ginned at too high speed, even the best 
varieties may be so damaged as to show large percentages of card 
and comber waste. The mixing of long and short staple seed, at the 
gin or otherwise, results in the production of cotton lacking uni- 
formity or " body." 
