Today is 4th April 2015, Our clipping is precisely 100 years old.
It wasn't the Gazette de France.
Thank you for your help, Christian Bach, but it was in vain.
I am now going to contact the librarian/archivist at Chambord to find out about the fire in the beginning of April 1915. Could it be possible after all these years that they have a copy of the clipping too?