This week, the World-Weary women review a few of history's most mind-boggling mechanical inventions. From flying wings to ferris wheels, Cassiopeia looks at the armoured tank designs that didn't quite make it to the battlefield. Violet presents Zhang Heng's Lost Seismoscope: a sophisticated ancient earthquake detector that has baffled experts for almost two millenia. Music: Creepy Tricky by Readfs.com. Licensed under Creative Commons: By Attribution 3.0 License.