Auction 333-341 Western Australia & Great Britain - Day 3

Parallel-Motion, 1857: 1 d. red, Die II, perf. 14, lettered SL, used on cover, London to Ashburton, Devon, dated 14 May 1858, tied by the rare Pearson Hill Parallel Motion second Trial duplex cancel Type II in black, Machine 'C', Code A. To the reverse a London transit and an arrival towndated (MY 15). Cover is stained and soiled and there is a small perf. bend to the adhesive. However, a very rare survivor; the only known example from this Trial.  
Note: The second Trial of the duplex Postmark Type II officially commenced 13-14 May 1858. Hill's so-called 'Parallel-Motion Stamping Machine' was a modified, more robustly constructed Machine 'C' type, having a parallel-motion linkage and a double roller inking feature to eliminate offset inking on mail which was particularly prevalent with the earlier Trials.