THOMAS MITCHELL REGISTERED LETTER, BLACKALL QLD to STETTLER AB, CANADA
This is one of the many Royal Geographical Society of Australasia covers but there is added interest in that it was sent Air Mail and Registered to Canada as a First Day cover, and the reverse backstamping was quite a surprise. The postage adds up to 2 shillings and 9 pence, made up of the complete Thomas Mitchell set (plus and additional 1 shilling copy) and a single of the