GSGS series 4228. First Edition-AMS 1. Italian Istituto Geografico Militare map dated 1928 and photolithographed by the British Ordnance Survey in 1943. Reprinted by the U.S. Army Map Service in 1944. The meridians are based on the meridian of Rome, which is 12 degrees, 27 minutes and 7.1 seconds east of Greenwich. Contours at 20 metres (V.I.). North Italy Grid.