Aramis Antiques has dated this piece to the 1860s.
The stool stands on four turned solid legs, United by stretchers to the central pedestal, containing the steel revolving mechanism. The mechanism works perfectly, easily achieving a change in height from 47 to 52cm (and maybe more). The stool is in excellent condition for its age, as is the tapestry top.
Aramis Antiques has dated this piece to the 1860s.
You can view the stock and full dealer information on the Aramis Antiques Profile Page