Shortly after this Charles Renard , commander of the French Army balloon school at Chalais Meudon , invited Ferber to join this establishment .
Ferber took up this new post in early May 1904 .
Shortly after this Charles Renard , commander of the French Army balloon school at Chalais Meudon , invited Ferber to join this establishment , and he took up this new post in early May 1904 .