194 A. S. Kimball—Journal Friction at Low Speeds. 
In order to eliminate as far as possible gradual changes in 
the condition of the rubbing surfaces, the following order of 
observation was adopted in each series. Calling the slowest 
speed No. 1, four observations were made alternating 
between Nos. 6 and 1. 
“ .T4 2. 
7. BE ees 
(74 6 
5, ete. 
1, 
a 
& 
me ho OH Ee 
a 
“cc 6. 
lower speeds were decisive. The most probable values of the 
coefficient as shown by a graphical construction of all these ex- 
periments is shown in 
BLE III. 
Speed, Noe 48 47 10 AG ay 40" 40. 60° 00 
Coefficient, 150 *122 -104 -093 -079 -066 -058 ‘054 053 °052 -051 050 
Thus we see that the conditions under which journal friction 
usually occurs are such that the maximum coefficient will be 
found at a very low speed. While using a journal 6” in diam- 
is great in comparison, or on the other hand so great as to pro- 
duce abrasion. An experimental examination of this point 
turbing slightly the adjustment of the machine. These results’ 
as the specific pressure on the journal increases even when the, 
pressures are quite large. 
