4 BULLETIN 1168, U. S. DEPARTMENT OF AGRICULTURE. 
The shoes were issued only to privates and were carefully fitted by 
Army officers. Each private kept a card record of the wear of his 
shoes, which was checked from time to time when the shoes were 
inspected. 
The worn-out shoes were sent to Washington for final inspection. 
After the observations and ratings from this inspection had been 
recorded, the worn soles were removed in the Bureau of Chemistry 
for examination, analysis, and comparison with the original leathers. 
RESULTS OF INVESTIGATION. 
Because of the frequent changes in officer personnel and the rapid 
discharge at the close of the war of soldiers, to many of whom ex- 
perimental shoes had been issued, much information was lost. The 
results therefore are not as complete as they otherwise would have 
been. For this reason it is inadvisable to base detailed conclusions 
on this work, or to stress the direct comparison of one lot of leather 
with another. 
Certain broad, general conclusions, however, appear to be warranted 
for the wear conditions of these experiments, especially in view of the 
fact that these tests included more shoes, more kinds of leather, and 
more comparisons than any other similar experiments 
CONDITION OF WORN LEATHER. 
All statements concerning upper leathers, types of shoes, and fiber 
soles are based on the ratings given in the inspection of the worn 
shoes. 
Upper Leathers. 
At the end of the investigation the upper leathers of all types were 
in good condition, only an occasional shoe upper showing material 
wear. However, the bark-tanned uppers were decidedly hard and 
stiff, 58 per cent being rated as too stiff or hard to wear with comfort 
or safety. This condition, while in general agreement with European 
observations in the field, may have been accentuated by the fact that 
the experiments were conducted in a section where the soil contains 
free alkali and where the climate is very dry. 
There was practically no difference between grain-finished stuffed 
chrome-tanned and fat-liquored chrome-tanned upper leathers. 
These leathers were pliable and retained well their soft dressed feel. 
The retanned chrome leather (chrome tanned and slightly retanned 
with vegetable tanning materials) seemed to be the best of all in 
pliability and softness, but was somewhat dryer or harsher than the 
stuffed or fat-liquored chrome-tanned leathers. The grain-finish 
retanned chrome leather had a better appearance than the flesh- 
finish leather and seemed to be more pliable and mellow. The 
upper leathers ranged from 2.3 to 3 millimeters in thickness. Leather 
of this weight is too heavy and thick for uppers, except possibly for 
winter trench wear or heavy outdoor work. 
The experiments were not continued long enough to determine 
the actual wearing quality of the upper leathers. It was evident, 
however, that, with reasonable care, upper leathers from 2.3 to 3 
millimeters thick would outwear three or more soles, and that these 
typical American upper leathers were capable of giving long service. 
