Great Britain. (Spain). 1851. Stamp-less envelope written from Leith dated '7th Aug 1851' addressed to Cadiz, cancelled by framed 'Castle Street' with 'Paid at Edinburgh' date stamp, rated '1.0/ 1,8 = 2/6d' in red m/s, endorsed 'via France' and routed via London with French entry cachet and oval 'P-F' (Paid to Frontier) and charged with hand-struck '36R' in red with Cadiz arrival on reverse.