This is a very rare and wonderful tea set with a large teapot fitted with a built in diffuser. Gorgeous repousse detail on all pieces and lovely tilting floral handles on the sugar cover and the teapot.  Note the elaborate detail on the handles and spouts.  This was made by Roswell Gleason and Sons in Dorchester MA, between 1850 and 1871.  Gleason & Sons were known for their clever and ornate designs, and have been collected by museums such as the Museum of Fine Arts, Boston.