Provisional GSGS series 4228. Second Edition (coloured)-AMS 3. Copied from an Isola Di. S. Pietro 1:50,000 map dated 1931 with principal communications revised to 1942 using air photos. The meridians are based on the meridian of Rome, which is 12 degrees, 27 minutes and 7.1 seconds east of Greenwich. Contours at 25 metres interval. South Italy Zone Grid "Blue".