GSGS series 4229. Second Edition (Coloured)-AMS 1. Copied from an Italian Istituto Geografico Militare map dated 1885 with principal communications revised to 1940 using maps and air photos. Compiled by the U.S. Army Map Service but photolithographed by the British Ordnance Survey in 1943. Road classification is NOT based on reconnaissance, reliability is uncertain. The meridians are based on the meridian of Rome, which is 12 degrees, 27 minutes and 7.1 seconds east of Greenwich. Contours at 10 metres interval. South Italy Grid (Blue). An inset map of Isola Ustica.