ABRASION OF THE SURFACES OF SOLIDS 
153 
Experiments 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. 
J Average. 
Weight 
on sur- 
face. 
Weight re- 
quired to 
move it. 
Proportion 
Weight per 
square inch. 
Average. 
Black Beech on Black Beech. 
Norway Oak on Norway Oak. 
CWt. 
lbs. oz. 
CWt. 
qrs. 
cwt. 
lbs. 
OZ. 
cwt. 
qrs. 
1 
8 6 
6.68 
0 
i 
1 
2 
8 
3 
6.83 
0 
i 
1 
15 5 
7.31 
0 
2 
l 
14 
5 
7.82 
0 
2 
2 
28 0 
8.00 
1 
0 
2 
26 
4 
8.53 
1 
0 
3 
45 3 
7.43 
1 
2 
3 
41 
3 
8.17 
1 
2 
4 
69 7 
6.45 
2 
0 
4 
56 
7 
7-93 
2 
0 
7.67 
5 
83 3 
6.73 
2 
2 
7.13 
5 
67 
3 
8.33 
2 
2 
6 
100 4 
6.70 
3 
0 
6 
80 
4 
8.37 
3 
0 
7 
115 11 
6.77 
3 
2 
7 
102 
0 
7.68 
3 
2 
8 
124 10 
7.18 
4 
0 
8 
164 
3 
5.45 
4 
0 
9 
132 3 
7.62 
4 
2 
10 
148 11 
7-53 
5 
0 
English Oak on English Oak. 
Hornbeam on Hornbeam. 
CWt. 
lbs. oz. 
CWt. 
qrs. 
CWt. 
lbs. 
OZ. 
cwt. 
qrs. 
1 
2 
7 0 
8.00 
0 
i 
1 
2 
8 
10 
6.49 
0 
i 
l 
15 0 
7.46 
0 
2 
l 
16 
3 
6.91 
0 
2 
2 
29 3 
7.67 
1 
0 
7.83 
2 
30 
5 
7.38 
1 
0 
3 
43 2 
7-79 
1 
2 
3 
46 
11 
7-19 
1 
2 
6.57 
4 
55 0 
8.14 
2 
0 
4 
65 
5 
6.85 
2 
0 
5 
70 3 
7-97 
2 
2 
5 
83 
1 
6.74 
2 
2 
6 
105 
2 
6.39 
3 
0 
7 
167 
3 
4.68 
3 
2 
Elm on Elm. 
Honduras Mahogany on Honduras Mahogany. 
CWt. 
lbs. oz. 
CWt. 
qrs. 
CWt. 
lbs. 
OZ. 
cwt. 
qrs. 
1 
2 
10 0 
5.60 
0 
i 
1 
2 
12 
7 
4.50 
0 
i 
l 
22 1 
5.07 
0 
2 
l 
26 
0 
4.30 
0 
2 
2 
35 5 
6.34 
1 
0 
2 
39 
3 
5.71 
1 
0 
3 
53 2 
6.32 
1 
2 
3 
39 
5 
5.66 
1 
2 
4 
72 3 
6.20 
2 
0 
5.86 
4 
74 
7 
6.01 
2 
0 
5 
87 11 
6.38 
2 
2 
5 
92 
3 
6.07 
2 
2 
5.96 
6 
108 4 
6.20 
3 
0 
6 
107 
6 
6.25 
3 
0 
7 
145 3 
5.39 
3 
2 
7 
118 
2 
6.63 
3 
2 
8 
168 11 
5.31 
4 
0 
8 
136 
4 
6.57 
4 
0 
9 
154 
1 
6.54 
4 
2 
10 
171 
0 
6.54 
5 
0 
11 
182 
3 
6.76 
5 
2 
Yellow Deal on Yellow Deal. 
White Deal on White Deal. 
CWt. 
lbs. oz. 
cwt. 
qrs. 
CWt. 
lbs. 
OZ. 
cwt. 
qrs. 
1 
2 
19 7 
2.88 
0 
i 
x 
18 
12 
2.98 
0 
i 
l 
37 9 
2.98 
0 
2 
1 
29 
5 
3.82 
0 
2 
3.81 
2 
76 3 
2.94 
1 
0 
2.88 
2 
48 
3 
4.94 
1 
0 
3 
113 0 
2.97 
1 
2 
4 
147 13 
3.03 
2 
0 
5 
224 0 
2.50 
2 
2 
MDCCCXXIX. 
x 
