Surely there has to be a link between the two? Yes, indeed there is. I discovered an essay on the sculptor of Rodenbach's tomb: 'Charlotte Besnard (1854–1931) : être femme sculpteur et épouse d’artiste en vogue, au tournant du XXe siècle' by Hélène Moreau-Sionneau. (Charlotte was the wife of artist Albert Besnard (1849-1934)). Moreau-Sionneau writes that Besnard sculpted the Rodenbach grave, on which was an inscription of a few now completely illegible lines of his poetry addressed to the Lord and praying for an after-life in literature. This tomb inspired Albert Roze (1861–1952) – commissioned by the Verne family – to sculpt the later grave, which is titled Towards Immortality and Everlasting Youth (Vers l’immortalité et l’éternelle jeunesse). Roze, with the aid of Verne's death mask, completed his work in 1907.