A glass retort is to be used under the conditions that the temperature of the inside of the wall is 100?C and the outside is 0?C. What stress will develop on the outside? The properties of the glass are α = 1.5 × 10-6/?C, E = 70 GPa, υ = 0.30. [Hint: Assume a linear temperature gradient and for simplicity take the midpoint strain as zero.]