Early 20th Century Slag Glass Lamp Edward Miller & Co. This is a wonderful slag glass lamp measuring 21 1/2 inches tall to the top of the finial shade is 16 inches in diameter. Base is 8 inches in diameter and marked EM & Co on the base. I do not believe the finial is original and the base has where to the green patina. It has been recently rewired and is working beautifully. The slag glass is in wonderful condition.