A complete strike of a Type 3 Glasgow Experimental Cancel and very controversially so named Madeleine Smith Cancel on piece. This short lived cancel is very scarce on cover or piece where the complete cancel is visible, its earliest known use was 10th February 1856 and latest known use was 12th June 1857. Type 3 is easily distinguished by the 3rd bar down on the left being unevenly spaced low, types 1 and 2 being evenly spaced. The font type in 'GLASGOW' is also thinner and the 'S' also has similar top and bottom loops.
This experimental cancel has quite an interesting history and gained notoriety due being linked to the famous murder trial of Madeleine Smith where the postmark became part of the evidence for the prosecution, as the postmark date was unreadable and the date of sending could not be proven Madeleine Smith was found not guilty of poisoning her lover with arsenic. MORE INFO