The associated claim that glass does flow over time is incorrect. “Evidence” is given by pointing out that early glass windows tend to be thicker at the bottom. This “evidence” is actually incorrectly attributed: glass panes with anything resembling a truly uniform thickness are a very recent advance. Until the early twentieth century, the only way to make a nearly flat sheet of glass was to start by blowing a globe or cylinder, then squashing it flat while it is still hot, either directly down onto itself or after cutting the shape open. The result is a glass pane with significant thickness variations, including typically one edge being thicker than the rest. Logically, these windows were usually installed with the thicker, heavier edge at the bottom. The idea that the glass of the windows has flowed down over time is completely contradicted by the fact that there are occasional examples of these glass panes being installed with the thick edge at the top or on one of the sides.