WEARING QUALITIES OF SHOE LEATHERS. 
The serviceability of such heavy upper leather therefore is of less con- 
cern than that of sole leather. 
J 
> 
Soling Material. 
Fiber soles of the kinds used were not suited for the wear conditions 
to which they were subjected, owing to the development of defects, 
such as ripping, breaking, and chipping, which, although important 
in the consideration of a satisfactory bottom stock, should here be 
distinguished from the property of resistance to the abrasive action of 
wear. 
Ripping from the stitches was a common fault of the fiber soles, 
some lots being worse than others in this respect. Frequently the 
soles ripped loose or broke off to the heel or shank when the edge of the 
sole wore through the stitches. One lot of fiber soles were stitched 
on by a representative of the firm supplying them and the others by a 
plant foreman with much factory experience with fiber soles. 
Many of the fiber soles of all of the makes bulged — that is, they be- 
came larger in area than the middle sole. Small pieces also fre- 
quently chipped off from the soles of two lots. 
The results in Table 1, expressed as percentage of the number of 
shoes inspected, show clearly the superiority, in the features just dis- 
cussed, of the leather soles over the fiber soles used. The data on 
fiber soles are given also by individual lots to show that not all of them 
developed the defects to the same extent. 
Table 1. — Proportion of soles that developed imperfections during tests. 
Soling material. 
Ripped 
or broken 
oflto 
heel or 
shank. 
Short rip 
only. 
Bulged .i 
Chipped 
or broken- 
orl 
pieces. i 
Vegetable-tanned sole leather 
Per cent. 
Per cent. 
7.3 
17.6 
16.1 
22.2 
12.5 
11.5 
15.6 
Per cent. 
Per cent. 
Waxed and unwaxed 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 
16.5 
Lot 02. 
20.9 
Lot 03 
Lot04 
i Observations on bulging and chipping, of course, could not be made on shoes from which the soles were 
entirely ripped or broken. 
Because of excessive toe wear and severe conditions of service, any 
ripping, chipping, or bulging tendencies were accentuated. It is 
probable, therefore, that the percentage of failures for fiber soles would 
be decidedly lower for civilian wear, particularly in cities. This 
point and the possibility that fiber soles, being entirely fabricated 
products, might be so modified as to overcome the defects discussed 
should be borne in mind, especially since the wear data (p. 8 and Hg. 2) 
show for the fiber soles which did not come off during the test a very 
high degree of resistance to wear, placing them second only to un- 
waxed chrome sole leather. 
The fiber soles were backed with a full middle sole of leather. 
While not the usual construction, it seems a desirable one, particu- 
larly from the standpoint of the comfort of the wearer. 
