I'll never pass by a good copper box if I can help it, and this is a beauty—as simple and honest as can be; just great lines and a fantastic patina. I found it with a book inside and believe it was indeed intended as a book box, but it would also be excellent for holding important documents, love letters, or old photos, or fill it with water and use it as a vase. Just a beautiful thing.
I posted a watering can a few months ago very similar in manner, I assume both Arts & Crafts. This box is in great condition, with one noticeable ding (indent) along the corner edge of one face and a bit of tearing at the corners of the lid; otherwise, a few very minor dings here and there and overall aging to the copper, which is much of what makes it so lovely. The underside of the lid shows some greening of the copper. 7 1/4" t x 4 1/2" w x 2" d (with lid on).