GSGS series 4229. Second Edition (Coloured)-AMS 1. Copied from an Italian Istituto Geografico Militare map dated 1931 with principal communications revised to 1942 using air photos. Compiled by the U.S. Army Map Service in 1942. The meridians are based on the meridian of Rome, which is 12 degrees, 27 minutes and 7.1 seconds east of Greenwich. Contours at 50 metres interval. South Italy Grid (Blue).