This three piece inkwell is marked "A.G. Whitcomb Improved."  It stands 1 3/4" tall and has a total diameter of 1 3/4".  Amasa G. Whitcomb was a Boston school furniture seller from 1876 to 1891.  These inkwells may not have been made by him, but for him by a pewter maker.  Few of these retain the glass insert.

Item #7-227