Clément Adrien Vincendon-Dumoulin 1811 – 1858

[aukepalmhof]

The stamp shows us on the 23.00F stamp a sailing vessel within the foreground a ships rowboat (without any crew, not any captain would have allowed that a ship's boat was left alongside a rocky coast without any crew) and onshore three men took measurement from something. The vessel is most probably the L’ASTROLABE, I could not find an exact painting or drawing on the internet after which the 23.00F stamp was designed. The drawing given on this page of the L’ASTROLABE which has a square stern looks about the same as on the stamp otherwise the design of the stamp is an image of the designer I believe. The 2.80F stamp depicts. Vincendon-Dumoulin a marine hydrographer.

Clément Adrien Vincendon-Dumoulin 1811 – 1858, born on March 4, 1811, in Chatte (Isère) and dies on May 12, 1858, at Chevrières (Isère) which is a marine hydrographer. He participates among others in the expedition of Dumont d'Urville to Antarctica, during which he will make the first calculation of the magnetic inclination thus allowing to locate the magnetic South Pole (January 23, 1838) as seen on the stamp of 23.00 F, and he will prepare the first map of Adélie Land (1840)

Expedition Dumont d'Urville .
In 1837 , on the proposal of Admiral Ferdinand Hamelin, who recommended him to Dumont d'Urville as "a wise and industrious man who would do good work", he was appointed to embark as hydrographer on L'ASTROLABE under command of Dumont d'Urville who is about to leave for the third time to New Zealand with two ships, L'ASTROLABE and La ZÉLÉE. It is during this voyage of more than 3 years (July 1837 - November 1840) that Adélie Land (Antarctic) (January 1840) is discovered; he will, moreover, be the first Frenchman to see Adélic Land from the mast.

His main mission is then to map the poorly known coasts that will be skirted by the two ships of the expedition. He is the “acclaimed author of a method of surveying coastlines accurately from a ship while under sail.
The two ships slowly sailed to the West, skirting walls of ice, and on 22 January, just before 9 in the evening, some members of the crew disembarked on the north-westernmost and highest islet of the rocky group of Dumoulin Islands, at 500–600 m from the icy coast of the Astrolabe Glacier Tongue of the time, today about 4 km north from the glacier extremity near Cape Geodesie, and hoisted the French tricolour.

Dumont named the archipelago Pointe Géologie and the land beyond, Terre Adélie,
The map of the coast drawn under sail by the hydrographer Clément Adrien Vincendon-Dumoulin is remarkably accurate given the means of the time.
In the following days, the expedition followed the coast westward then led for the first time some experiments to determine the approximate position of the South magnetic pole. They sighted the American schooner PORPOISE of the United States Exploring Expedition commanded by Charles Wilkes on 30 Jan. 1840 but failed to communicate due to a misunderstanding. On 1 February, Dumont decided to turn to the north heading for Hobart, which the two ships reached 17 days later. They were present for the arrival of the two ships of James Ross’s expedition to Antarctica, HMS TERROR, and HMS EREBUS.

https://en.wikipedia.org/wiki/Jules_Dumont_d%27Urville

More on the L’ASTROLABE is given on: viewtopic.php?f=2&t=7810

French Southern and Antarctic Territory 1994 2.80F and 23.00F sg 326/27 and scott 196.