One US 5 c stamps on envelope, cancelled "Brooklyn NY Mar 24 1931". On the left side, written with typewriter "Christening Sir Hubert Wilkins Under Sea Boat "Nautilus" Navy Yard Brooklyn, N.Y.", together with 7 signatures of the crew. The Nautilus sailed to Spitsbergen and attempted to reach the North Pole without success.

One US 5 c stamps on envelope, cancelled "Brooklyn NY Mar 24 1931". On the left side, written with typewriter "Christening Sir Hubert Wilkins Under Sea Boat "Nautilus" Navy Yard Brooklyn, N.Y.", together with 7 signatures of the crew. The Nautilus sailed to Spitsbergen and attempted to reach the North Pole without success.