152 
MR. RENNIE’S EXPERIMENTS ON THE FRICTION AND 
Table III. On the Friction with Cloth at different angles of elevation. 
Weight on 
surface. 
Moved at 
degrees. 
Space 
passed over. 
Time in 
seconds. 
Proportion. 
Weight on 
surface. 
Moved at 
degrees. 
Space 
passed over. 
Time in 
seconds. 
Proportion. 
Of 3 square inches. 
Of 27 square inches. 
lbs. 
inches. 
lbs. oz. 
o 
inches. 
10 
37.00 
24 
55 
1.327 
13 8 
45.00 
18 
32 
1.000 
20 
28.20 
55 
1.855 
20 0 
40.30 
42 
1.171 
28 
26.00 
47 
2.051 
28 0 
35.45 
32 
1.389 
56 
20.45 
44 
2.640 
56 0 
26.00 
28 
2.052 
1 . In comparing the results given by the angles of repose with the results given by the horizontal 
surfaces on similar kinds of cloth, there is a slight variation. 
2. The second series of experiments afford no measure of comparison, from the inadequacy of the 
weights of lOlbs. being unable to give motion to the upper surface, 13lbs. 8oz. gives an approximation. 
3. The less the weight, the greater the angle of repose. 
4. Increase of surface produces a very great increase in the angles of repose. 
The times very variable, diminish with increase of weight. 
5. Velocities likewise variable. 
Table IV. On the Friction of different Woods two square inches surface. 
Weight 
on sur- 
face. 
Weight re- 
quired to 
move it. 
Proportion. 
Weight per 
square inch. 
Average. 
Weight 
on sur- 
face. 
Weight re- 
quired to 
move it. 
Proportion. 
Weight per 
square inch. 
Average. 
Red Teak on Red Teak. 
American live Oak on American live Oak. 
cwt. 
lbs. 
OZ. 
cwt. 
qrs. 
cwt. 
lbs. 
OZ. 
cwt. 
qrs. 
1 
6 
14 
8.14 
0 
i 
1 
2 
7 
15 
7.05 
0 
i 
1 
14 
2 
7-92 
0 
2 
l 
14 
13 
7.56 
0 
2 
2 
23 
3 
9.66 
1 
0 
2 
25 
15 
8.63 
1 
0 
3 
38 
1 
8.82 
1 
2 
3 
36 
11 
9-15 
1 
2 
4 
52 
3 
8.58 
2 
0 
4 
55 
11 
8.04 
2 
0 
5 
64 
2 
8.73 
2 
2 
5 
70 
3 
7-97 
2 
2 
6 
71 
12 
9-36 
3 
0 
8.82 
6 
86 
3 
7-79 
3 
0 
/ .oo 
7 
84 
3 
9.31 
3 
2 
7 
109 
7 
7.16 
3 
2 
8 
90 
8 
9-90 
4 
0 
8 
128 
4 
6.98 
4 
0 
9 
120 
11 
8.35 
4 
2 
9 
140 
3 
7-19 
4 
2 
10 
126 
5 
8.86 
5 
0 
10 
154 
1 
7.26 
5 
0 
11 
141 
15 
8.67 
5 
2 
11 
162 
14 
7.56 
5 
2 
12 
154 
3 
8.71 
6 
0 
12 
187 
5 
7-17 
6 
0 
13 
170 
10 
8.53 
6 
2 
Pine on Pine. 
cwt. 
A 
2 
1 
2 
3 
lbs. 
16 
27 
68 
m 
oz. 
3 
14 
4 
5 
3.33 
4.01 
3.27 
3.01 
cwt. 
0 
0 
1 
1 
qrs. 
1 
2 
0 
2 
3.40 
