Hi Jim, I know of this design and played around with in once but gave it up for the simpler version. This type of oven uses forced air into the burn chamber to get a good fire going and because of the speed of the flow through, the flames continue to carry most of the heat with them up and away, hence the after burner/heat exchanger idea. If you just are a little patient and let the fire burn out slowly in the first place then there is no need for all the extra design and so on. It could be that this oven would act as a low tech masonry heater in some situations, but again its a bit too much of a compromise for me. The cast iron doors for these ovens are still manufactured today under the name of "Dutch Oven" doors.
ALAN SCOTT - 10/4/02

Your friend may have seen a "reproduction" bake oven that we use with our educational programs in an area outside the museum, or an oven installed as part of a baking exhibit on the 5th floor of the museum. The former is not a particularly good or authentic model, though built with the "squirrel tail" idea in mind. Unfortunately, we do not have existing photography for either. We do, however, have some materials in our research files here that we could copy for you, and our library may have additional information, perhaps in Henry Mercer's research notes.

There is a $15 fee for curatorial search/photocopying services, plus $.50/per page. If you are interested let me know and I will forward your query to our curatorial assistant to do the search and copying of materials. Of course, you are also welcome to arrange a research visit to the Mercer if you are able to travel east.

Thanks very much for your interest and let me know if we can be of service.

Cory Amsler
Curator