Well used school books, they have been battered in a school satchel, annotated, pages have been lost and the spines are a loose. A bit of the cover from the Lectures Elémentaire has ripped and the Langues Française is creased. But they have oodles of character and look every one of their 100 years. A perfect French timeworn prop. 
You could still do some of the lessons and the homework! 
They measure 18cm by 12cm or 7" by 5" approximately, the 'Langue Française' is very slightly bigger. 

Trio of 1920s antique French school books