This chart is similar to the Jim Lewis' Astro*Carto*Graphy map, i.e. a map of the earth is displyed, crossed by straight or curved lines. Those lines show the longitudes of where on Earth at that time the regarded objects are on the midheaven or on the nadir, and the latitude of where the planets actually appeared at zenith, and also the longitude of where the objects appeared on the ascendant and descendant is displayed.

If you click on a region on the chart, a zooming is performed, and displays more and more precise details of the Earth. From a 128x zooming, the local cities on the map are also displayed. Press the Ctrl key while clicking on the map, and the map will be zoomed out.