Bidspirit auction | Worldwide Air Post Stamps and

Worldwide Air Post Stamps and Postal History - Great Britain - Dirigible Flight - 1925, The Grettir Algarsson North Pole Expedition, specimen envelope carried from London to Liverpool by dirigible, which was supposed to fly from Svalbard (Spitsbergen) to North Pole (this flight did not take place because of lack of funding), pre- printed at the bottom with text and number 66, blue flight label and downward ''Specimen'' hs, mostly VF, Est. $180-$200