24 BULLETIN 1168, U. S. DEPARTMENT OF AGRICULTURE. 
Well-oiled leathers. — The results on leather oiled in various ways 
are not satisfactory, because the differences in oil contents of the 
lots were not sufficiently great. The indications are that the sole 
leathers of normal oil contents wear about 8 per cent longer than do 
the well-oiled leathers. This indication needs further confirmation 
before it can be accepted as final. 
Acid tannage. — Leather from the acid tannages did not wear quite 
as long as that from the nonacid tannages. For several reasons, 
however, this is not regarded as conclusive. 
Section of the lend. — The average wear per 9 irons for soles from 
the shoulder end of the bend was 79 days, as against 85 days for those 
from the butt end. These indications are in harmony with practical 
experience and with other experiments on leathers from the different 
sections of the hide. 
The outstanding indications from this investigation, which was 
conducted under very dry conditions, are : (1) The superior pliability 
of retanned chrome and chrome-tanned upper leathers ; (2) the objec- 
tionable features of fiber soles and the long wear of those that did not 
develop such features ; (3) the longer wear, thickness for thickness, of 
roUed vegetable-tanned sole leather as compared with that of the 
corresponding unrolled leathers ; and (4) the strikingly longer wear of 
chrome-tanned sole leathers, especially of the unwaxed chrome-tanned 
leather. 
WASHINGTON : GOVERNMENT PRINTING OFFICE : 1924 
