One of the leading engineers involved in the recent rescue of the Leaning Tower of Pisa, which barely escaped collapse, gave a public talk about the project at the University of Reading. Among other things, he presented an interesting chart. On the horizontal axis was time, and on the vertical axis was the distance between the base of the tower and the point on the ground directly underneath the leaning top. When the measurements started being taken around the beginning of the last century, that distance was some four meters. It grew by half a meter or so by the end of the century. So, the line on the chart gradually goes up. However, at several points there are sudden jumps. These were of special interest, of course. Why would the condition of the tower worsen so rapidly at these particular times? As it turned out, these jumps marked all previous attempts to put the tower right.