or GLASS, AND THE RESISTANCE OF GLASS VESSELS TO COLLAPSE. 237 
Experiment 16. 
Cylinder Q. Diameter 4'06 inches. 
Length 13-8 inches. 
In parts of an inch. 
'0-0448' 
0-050 
0-0474 
Thicknesses measured < 
0-0490 . ^ 
0 0476 I =0-043 inch. 
Thicknesses measured < 
>- Minimum =0-064 inch. 
0-0470 
0-053 
.0-0434J 
Collapsing pressure =180 lbs. per square inch. 
Experiment 17. 
Cylinder R. Diameter 4-02 inches. 
Length 13-8 inches. 
In parts of an inch. 
'0-0678'' 
0-0664 
0-0728 
0-0718 
0-0660 
0-0644 
0-0706 
.0-0682. 
Collapsing pressure =297 lbs. per square inch. 
Experiment 18. 
Cylinder S. Diameter 3-98 inches. 
Length 14-0 inches. 
In parts of an inch. 
-0-0792' 
0-0774 
0-0762 
0-0812 
0-0828 
0-0848 
0-0836 
0-0778 
^0-0766- 
Collapsing pressure =382 lbs. per square inch. 
2 K 
Thicknesses measured < 
> Minimum =0-076 inch. 
Fig. 16. 
Fig. 17. 
Fig. 18, 
MDCCCLIX. 
