GSGS series 4228. Second Edition (coloured). Italian Istituto Geografico Militare map dated 1936 and photolithographed by the British Ordnance Survey in 1943. This sheet shows revision to principal communications up to 1939 from smaller scale maps. 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 (V.I.). South Italy Grid (Blue).