From Wikipedia Bois de Boulogne “is a large public park located along the western edge of the 16th arrondissement of Paris, near the suburb of Boulogne-Billancourt and Neuilly-sur-Seine. It was created between 1852 and 1858 during the reign of the Emperor Louis Napoleon.”
No clue why the clock was there. Or even what year the picture is actually from. By today’s standards it’s not that interesting, or complicated. But no doubt it was pretty cool back then.