1. Some of the labels in Fig. 1 are incomplete. They should read as follows: L/w=0.3, L/w=0.4, L/w=0.5, L/w=0.6 and L/w=0.7, L/w=0.8, L/w=0.9, L/w=1.0, L/w=1.1, L/w=1.2, L/w=1.4, L/w=2.5 and 5.
2. The origin of the x-y coordinate system referred to in the text is located at the center of the hole in Fig. 1.
3. In the next to the last paragraph the text should read “uniform displacement” instead of “uniform loading.”