Created by Louis Cartier in 1917, the Tank has been a go-to timepiece for a century’s worth ... and a winding crown topped with a blue sapphire (or in rare cases, ruby) cabochon. Wait, Why Is the ...

And others say Louis Cartier made the Tank as a pioneer of design for Art ... and tilt to circumscribe the outer rim, while two blue hands trace the chemin de fer – the train track-looking ...