166 
MR. RENNIE’S EXPERIMENTS ON THE FRICTION AND 
Remarks on Table X. 
The deductions to be made for the rigidity of the cord used in the foregoing experiments under 
variable weights, as shown in the second and third columns, are nearly as the weights simply, and are 
applicable to most of the cases in Table IX. 
Table XI. Experiments on the friction of Ice. 
A block of ice eighteen inches long and two inches thick, as free as possible 
from air-bubbles, was accurately prepared so as to present a smooth, flat 
surface, and was then fixed on the frame. A piece of the same block of ice, 
but of smaller dimensions, was accurately prepared, and made to glide with 
its flat surface over the bottom block, and a fine flexible silken cord attached 
to it as in the former experiments. 
The weights in the first column indicate the insistent weights, and the weight 
in the second column the moveable weights. The experiments were made when 
the temperature of the atmosphere was about 28 degrees of Fahr. 
Sixteen inches 
surface. 
With two skates 4| inches long, by 
surface in each. 
-nr wide, in 
Weight on 
surface. 
Weight required 
to move it. 
Proportion. 
Weight on 
surface. 
Weight required 
to move it. 
Proportion. 
lbs. 
oz. 
lbs. 
OZ. 
lbs. 
OZ. 
lbs. 
OZ. 
1 
8 
0 
3 
8.00 
1 
8 
0 
1 
24.00 
4 
0 
0 
5 
12.80 
4 
0 
0 
3 
21.33 
16 
0 
0 
10 
25.60 
16 
0 
0 
7 
36.57 
36 
0 
1 
0 
36.00 
36 
0 
0 
15 
38.40 
64 
0 
1 
6 
46.54 
64 
0 
1 
2 
56.88 
81 
0 
1 
13 
44.68 
81 
0 
1 
10 
49.84 
144 
0 
2 
9 
56.19 
144 
0 
2 
1 
69.81 
After remaining 
16 hours 
lbs. 
OZ. 
lbs. 
OZ. 
1 
8 
0 
3 
8.00 
4 
0 
0 
6 
10.66 
16 
0 
0 
15 
17-06 
36 
0 
1 
9 
23.04 
64 
0 
3 
2 
20.48 
81 
0 
4 
0 
20.25 
144 
0 
6 
5 
22.81 
REMARKS. — From the foregoing experiments it appears, that with ice on ice, friction diminishes 
with an increase of weight, but does not seem to observe any regular law with regard to that increase. 
