What language is this and what does it say? (Characters identified: 下角) This is stamped on the bottom of pieces of a tea set (cups, saucers, tea pot,etc) my father bought for his mother during WWII. I believe he purchased it in Shanghai prior to 1945.

Can someone please tell me what it says and in what language?
It's a seal with Chinese characters 下角.
As Tang Ho said, It could be a brand name/place name of origin/craftsman name etc.