WEARING QUALITIES OF SHOE LEATHERS. 5 
Those results are in harmony with the general experience that shoe 
uppers made from the better portions of cow grain leathers of good 
quality will outwear two or more soles. The question of the service- 
ability of such heavy upper leather is of less concern than the service- 
ability of sole leather. 
Soling Material. 
Fiber soles of the kinds used were not suited for the conditions of 
wear to which they were subjected, owing principally to the fact that, 
as soon as the edge of the sole became worn down through the stitches, 
the sole had a decided tendency to rip or break off. In making up 
the shoes for these experiments, one lot of fiber soles was stitched on 
by a representative of the firm supplying them and the other lots were 
put on by a plant foreman who had had a great deal of factory ex- 
perience with fiber soles. 
The tendency to rip off is not as general with some lots as with 
others (Table 1). Practically all of the fiber soles, regardless of 
make, showed a strong tendency to bulge, that is, to become larger 
in area than the middle sole. The results show that the fiber soles 
which did not come off during the test wore very well. 
Table 1 gives the imperfections of the soling materials which 
developed during the test, expressed as percentage of the number of 
shoes inspected. 
Table 1. — Proportion of soles that developed imperfections during tests. 
Soling material. 
Ripped 
or broken 
off to 
heel or 
shank. 
Short rip 
only. 
Bulged. 
Chipped 
orbroken- 
off 
Vegetable-tanned sole leather 
Per cent. 
Per ct. ni . 
7.3 
17.6 
7.6 
22.2 
12.5 
11.5 
15. 6 
Per cent. 
Per cent. 
Waxed and un waxed chrome-tanned sole leather 
Fiber: 
All lots 
23.7 
13.8 
4.2 
11.5 
59.3 
28.8 
27.7 
20.9 
38.4 
28. 1 
8.3 
Lot 01 
16 ■> 
\ Lot 02 
20.9 
9 Lot 03 
Lot 04 
Observations on bulging and chipping, of course, could not be made 
on shoes from which the soles were entirely ripped or broken. The 
data on the individual lots of fiber soles are given to show that not 
all of them possess physical imperfections to quite the same extent. 
The type of shoe and the conditions of wear were such as to accentuate 
the ripping, bulging, and chipping tendencies of the fiber soling mate- 
rials. It seems probable, therefore, that for civilian wear and in 
cities the percentage of failures from these causes would he decidedly 
lower. 
Since the conditions of service during these tests were comparable 
for practically all shoes, the results leave but little doubt as to the 
superiority of leather soles in the features just discussed, as com- 
pared with the fiber soles used in these experiments. The fiber soles 
were backed with a full middle sole of leather. Although not the 
ordinary construction, this seems desirable for fiber soles, especially 
from the standpoint of comfort. 
