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

1864 (April 1): 1 d. red, plate 81, lettered TK, used on cover, sent locally within London, tied by a fine strike of the Charles Rideout Experimental Machine number '1' duplex cancel, Type II, Code 'HS' in black, from the second Trial, dated 12 October 1866. To the reverse a London EC arrival cds in red (Oct 12). Minor soiling. A fine and rare example; one of two reported covers.
Note: Although the Pearson Hill Parallel Motion Machine had been selected by the London Post Office in 1859 for wide-spread use, Charles Rideout pressed for additional trials and in 1866 the GPO conducted a second trial which was also not successful for Rideout.