Not sure who manufactured this inkwell, but it is marked on one of the glass wells. (Last photo.  "Pat. Oct. 8, 1912".  9 1/2" long by 5" wide by 1 1/2" at the highest.  "Steps for pens and pencils gradually increase.  Very good condition.  The only defect I find is the roughness I can feel on the left well at the rim.  See fourth photo. Edges aren't sharp, rather they are cut on a diameter. Whoops! Just spotted a smooth (old) chip on bottom right, where a pencil would rest.