Rumford Technical Discussion
Milner - an English Rosin
Date: 11/1/06
To: David Scott
From: Jim Buckley


Thanks. Your Milner is what we call a Rosin in the US. My evaluation, as I say at is:

    [The Rosin fireplace is] a modification of a Rumford by a man named Rosin who developed the modification in the 1930's. Rosins are good fireplaces but I'm not convinced they are better than Rumfords. Rosin, himself, was very modest in his proposal which was based on scale modeling and so subject to errors of scale. He also didn't use heat. His models involved dropping salts in a fluid through a small scale model fireplace and observing the "streamlines" by taking time exposure photographs of the salts falling through the fluid. Trying to maximize radiation, Rosin suggested a parabolic shaped "modern" firebox shape rather than one made of firebrick and to minimize turbulence he recommended streamlining the exit to the throat as well as the entrance as Rumford did. So, is it better? I don't know since none of the Rosins - Belfires in New York or Frisch Rosin in Washington - have been built as Rosin suggested and, in any configuration, have not been tested (or if they have the results have not been made public) for emissions or efficiency as an open fireplace. I believe Belfires has an "optional" stainless steel Rumford throat modeled after our Rumford throat but not the hour glass shaped throat Rosin advocated. The claims for improved aerodynamics or cleaner-burning are all sales propaganda in the absence of third party test data.
Rosin's original essay, "The Aerodynamics of Domestic Open Fireplaces" was published in England in the Journal of the Institute of Fuel, Vol 12, 1939, pp. 198-224.

Jim Buckley


Hello Jim

I've scanned in some images of Milner firebacks from product catalogues, and I've attached a pdf with fitting instructions.

The following are manufacturers' websites:

Hepworth Insturctions

Hope this helps to describe the "Milner". I wonder if it was developed from the Rumford? Information doesn't seem to be too readily available. I don't know if it would work with logs stacked on end.

I'll send pictures of the fireplace opening in due course.

Best Wishes
David Scott

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