ABRASION OF THE SURFACES OF SOLIDS. 
151 
Remarks. 
1. That with fibrous substances, such as cloth, friction diminishes with an increase of weight. 
2. That friction is greater (caeteris paribus) with fine cloths than with coarse cloths. 
3. That friction is greatly increased by time. 
4. That friction varies from one-third to an amount greater than the total weight. 
Table II. Experiments on the Velocities with Drab Milled Kerseymere, No. 3. 
Weight on 
surface. 
Weight required 
to move it. 
Total space 
passed over. 
Time in seconds. 
Remarks. 
Of 9 square inches surface. 
lbs. 
1 
5 
10 
20 
lbs. oz. 
1 8 
1 5 
2 5 
2 5 
4 3 
6 7 
9 7 
inches. 
24 
45 
32 
30 
22 
23 
24 
25 
40 
37 
31 
26 
mean of 3 trials 
17 
27 
21 
30* 
33 
53 
17 
30* 
29 
45 
45 
63 
30 
50 
From lib. to2lbs. the adhesion 
is greater than the weight on 
surface. 
Velocities very irregular. 
Velocities very irregular. 
* Denote the experiments that 
approximate the nearest to an 
uniform velocity. 
Results very irregular, owing 
perhaps to the fibres of the 
cloth having been previously 
compressed. 
Of 18 square inches surface. 
lbs. 
lbs. oz. 
inches. 
1st half. 2nd half. 
Increase of surface shows an 
20 
13 6 
mean of 3 trials 21 
22 33 
increase of resistance with 
after remains 14 hrs.i « 
equal weights of 20lbs. 
,4\) 
it took to start it J o 
Time nearly doubles the resist- 
ance. 
Of 27 square inches surface. 
lbs. 
lbs. oz. 
inches. 
1st half. 2nd half. 
Three times the surface nearly 
1 
2 8 
mean of 3 trials 18 
4 14 
three times the resistance. — 
2 
3 10 
30 73 
Velocities irregular. Vide 
5 
6 7 
25 60 
Vince’s Experiments. 
10 
10 2 
28 55 
Nearly uniform. 
1 . From the foregoing experiments it appears that velocities observe no particular law, except in 
three instances, where the last halves of the space passed over approximate to the first halves. 
2. That increase of surface very much increases the resistance. 
