Jasper County Democrat, Volume 19, Number 14, Rensselaer, Jasper County, 17 May 1916 — Remarkable Swaying Tower. [ARTICLE]

Remarkable Swaying Tower.

By t lie mere pressure of your hand you can rock "Bather Campanile,” the 2 0 2-foot memorial tower just completed on the campus of the University of California. In order to minimize the danger from earthquake shocks the architect, Prof. John Galen Howard, and the engineer, Prof. Charles Derlith, jr., so built the strong steel frame of the Campanile that cross-bracing in eliminated at alternate stories. As a result the vibration of the tower is like that of a steel rod one end of which is thrust in the ground. In an earthquake the tower would vibrate like a tree. According to Prof. Elmer E. Hall’s tests the tower has a vibration of 1. 1 3 seconds. By pressing against the steel frame at the top of the Campanile every 1.12 seconds he was able to rock the tower, so that earthquake recorders (seismographs they Hl'e called ) registered the vibrations. However, the amount of motion was less than the thickness of this sheet of paper. The plan on which the tower was built is to prevent a re-enforcement of liie rocking caused by an earthquake vibration. For instance, a child can set. a hammock swinging violently simply by pushing at the right moment, no matter how heavy the load may lie. If the pushes are not timed correctly, the swinging is retarded. It is the same with the <':impanile. The. plan is to prevent cumulative swaying, such as would occur if the period ot the earthquake and the vibration of the tower were the same, and such as would cause the structure to collapse. Mrs .Jane, K. Bather erected the memorial to her husband. Popular Science Mont lily. \