Cadran Solaire Vertical

Vertical Sundial

Many sundials can be found in Paris, 

either high on a building (to catch the sun's rays)

 or on the ground.  

This one is vertical and found in Montmartre.

Vertical Sundial

Montmartre

75018, Paris

Quand tu sonneras...

Vertical sundial

Paris is full of sundials, horizontal and vertical,

and many like this on in Montmartre are incorporated into the original architecture. 

There is a book on this subject,

in French and out of print, but I am still searching.

Vertical sundial

Montmartre

75018, Paris