The word "Ariake" means the moon that remains in the sky as morning dawns.  
Ariake lights, like their name, were left on throughout the night and had a beautiful glow. 
Each light had a cover, which was a box with a full moon-shaped window on the front and half moon-shaped windows on the sides.  When used at night, this cover was placed over the lights, illuminating the moons and weakening the light. If our modern eyes, which are continually surrounded by bright lights, were to look at an Ariake light with its cover on, we would see only a faint glow and may not appreciate it.

ARIAKEANDON, lights representing the Edo period