Due to age and heavy scratching on the bottom, the initials are very hard to read.  We were able to read some numbers that look like 41048.  We hope you can read it in the photo.  The scratches are also hard to see in the pictures.

The glass measures 8 1/2" diameter and 1 1/2" high.  The snail in the center with the indent around it led us to believe that this could be used as a pipe ashtray.