Charles Petit continued his diving apparatus manufacturing business into the 1920s. In 1926 his daughter married Rene Piel who came to work for the company. For some time both family names (Charles Petit & Rene Piel) were marked on the diving apparatus, but when Charles Petit died in 1930 the company was renamed ‘Rene Piel’.  Diving apparatus with both names on the company badge are rare but still occasionally seen (see pictures below).

1920 - 1930 Charles Petit & Rene Piel / Denayrouze.

This Modele 1889 ‘Clampage’ helmet was made during the time when Charles Petit and Rene Piel works together, as the company badge has both names stamped on it. Helmet: private collection. Photographs, David L.Dekker

The 3-cylinder Denayrouze air-pump exists in three versions: the Modele ‘Fluviale’ (‘river pump’) is the smallest version. The pump shown in the above photographs is the Modele ‘Moyenne profondeur’ (‘medium depth’ type) and the third version is the large Modele ‘Grand Profondeur’ (‘great depth’ type; also known as the modele ‘Marine’, or ‘Navy’ type). The pump in the photographs above was manufactured at the time when Charles Petit and Rene Piel worked together as it has both names on the company badge. I found this pump last year (2010) in Belgium. Photographs, David L.Dekker