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The Count and His Rumford Fireplace

Benjamin Thompson aka Count Rumford invented the Rumford fireplace.

Benjamin Thompson aka Count Rumford invented the Rumford fireplace.

"Observations on the Forgotten Art of Building a Good Fireplace" by Vrest Orton recounts the life of an actual person named Benjamin Thompson who became Count Rumford and invented the most efficient fireplace of similar name: the Rumford fireplace.

Serendipitously I came across this discovery in a used bookstore. What the 1974 (2nd ed.) paperback overlooked is that these "good fireplaces" are still being built today.

The author was perplexed why a mason who was repairing his fireplace would ever remark, "Look at that funny fireplace! With that opening it won't draw!" (Orton, p. 11). Yet it had already been doing so the entire time he had lived there with no smoke ever entering the house. He wondered why? And now so did I.

But first the history part. Who was Count Rumford?

Historic Rumford Fireplace

This brick Rumford fireplace served heating & cooking duty.

This brick Rumford fireplace served heating & cooking duty.

Living in Colonial America

This is an exciting topic from the standpoint that what pertained in the 1700s is of current interest. That said, we're talking about an expatriate and someone that many have not known about from their American History classes.

First and foremost, Count Rumford was curious and cunning. As a boy he preferred learning about how things worked and insisted on challenging his intellect particularly in mathematical matters. Throughout his life he had an uncanny ability to obtain political favors and advancements.

Born Benjamin Thompson in 1753 on his family's farm in Woburn, Massachusetts, at 13 he walked to attend lectures at Harvard. He was unable to obtain a formal education and apprenticed with a doctor. This boy was definitely not interested in the drudgery of farm duties.

Meanwhile, the rumblings of the American Revolution (1775-1783) were afoot. At 19 he had moved to Concord, New Hampshire (formerly Rumford), worked as a schoolmaster, married a well-connected widow, and befriended the British Royal Governor who commissioned him major in the NH militia without any training. For experienced soldiers and rebel sympathizers his appointment caused detest and suspicion.

Was he also a Tory spy? This question of motive led to accusations, resulting in his ultimately leaving with the British from Boston in 1776.

He returned once, in 1781, to recruit cavalry on Long Island. Back in London he served as under Secretary for the Colonies, and eventually became a British citizen.

Profile of Count Rumford in uniform.

Profile of Count Rumford in uniform.

Living in Europe

Thompson was appointed colonel in the regular army after war's end (1783). While visiting Bavaria he befriended the Elector who also requested his service. In 1784 back in England, he received leave permission (with half salary for life) and was knighted by the King.

He returned to Bavaria as Sir Benjamin Thompson and stayed from 1785-1796. Rising up through the ranks (aide, general, councillor), he organized the military, employed the poor, amended living conditions, designed a park, initiated workers education, and so forth. Decorated Graf von (Count of) the Holy Roman Empire was a major highlight. Since a count needs a county, he chose Rumford (Concord NH's former name), and shortened his title to Count Rumford.

Living in the Enlightenment

To improve living conditions for the public good, the Count turned to his scientific mind to seek solutions. He was living in the Age of Reason (1685-1815) when the rational approach of learning through observation, experimentation, and discourse was encouraged.

Gunpowder experiments roused his curiosity (and the Royal Society's membership in 1779) about the nature of heat. Considered a fluid substance called caloric, Rumford determined that heat was a form of motion. Thus, he was one of many to formulate the theories of thermodynamics (movement of heat and energy).

The related topic of heating homes he vowed to address in 1795 when he took leave from Bavaria to publish his works in London. The smoke problem (inside and out) from burning coal was of particular concern. Consequently, he devised a way to improve fireplace efficiencies.

In 1799 Rumford visited Paris, then Munich, then Britain. After Napoleon let him return to Paris, he married and divorced chemist Lavoisier's widow. The inventor continued working while living in nearby Auteuil, France, where his daughter Sarah came to care for him until his death in 1814.

Statue of Sir Benjamin Thompson, Count of Rumford, installed in 1900, Woburn Public Library, Woburn, MA (his birthplace).

Statue of Sir Benjamin Thompson, Count of Rumford, installed in 1900, Woburn Public Library, Woburn, MA (his birthplace).

Chimney fireplaces with proposals for improving to save fuel; to render dwelling-houses more comfortable and salubrious, and effectually to prevent chimneys from smoking."

— Count Rumford

What Makes A Fireplace A Rumford?

The Count was interested in improvements for the public at large known as the "useful arts" of what people did where they lived. How their fireplaces worked was of utmost importance. He posed changing the common (conventional way) of building.

His drawings (shown below) from "Essay IV: Of Chimney Fire-places" in Volume II (1873) of his Collected Works easily distinguish common and Rumford fireplaces in 1796.

Accolades for the Count

Some of his contributions were:

  • Establishing awards for heat or light research at the Royal Society (Rumford Medal) and the American Academy of Arts and Sciences (Rumford Prize) (1796).
  • Founding the Royal Institution to support the practical application of science (1799).
  • Bequeathing his works to Harvard whereby the Rumford Professorship was initiated in 1816.
  • Inventing the Rumford fireplace (1796).

Elevation Views

Looking at single face of Common & Rumford fireplace diagrams.

Looking at single face of Common & Rumford fireplace diagrams.

Elevations above - Figure 2 peers into a black box whereas Figure 4 reveals two sides winging out. These angles called covings better radiate heat to warm bodies of people and objects in the room.

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Plan Views

Looking down from above at Common & Rumford fireplace depictions.

Looking down from above at Common & Rumford fireplace depictions.

Plans above - The sides of Figure 1 are 90 degrees. Figure 3 builds out the back wall to lessen depth and reduces width to splay (taper out) covings by up to a 135 degree angle. These changes cause more heat to radiate out.

Section Views

Looking at a cross-section of Common & Rumford fireplace drawings.

Looking at a cross-section of Common & Rumford fireplace drawings.

Sections above - Figure 6 depicts another perspective of building out from the back of the fireplace to radiate heat. Unlike Figure 5, Figure 6 also creates a narrow channel that intersects upper and lower chambers. A rounded protrusion gently tapers down (on the left), while the built-up back (Rumford used bricks) creates a ledge (on the right). The swirly motion of combustion smoothly glides (without turbulence) up through the channel. Moving fire-combustion particles mix with fresh air at the ledge, then continue through the upper chamber and out the chimney top. Figure 6, the Rumford configuration, improves fireplace efficiency of movement known as draft.

Figure 6 Update

Figure 6 above corresponds fireplace terms to current Rumford elements.

Figure 6 above corresponds fireplace terms to current Rumford elements.

What Became of the Count's Fireplace?

After the 1850s fireplace dominance gave way to furnaces for heat and stoves for cooking. Architectural period revivals in the 1920s revived the fireplace with splendor prioritized over efficiency.

The Count's method had almost been lost. Environmental concerns and green practices have reinstated the Rumford in building code preferences and present-day fireplace selections.

Differences Persist

Distinctions continue to define standard versus Rumford fireplaces.

Take the dimensions of a 60 inch model, for example. (Fireplaces are sized by opening width.) The Rumford is taller (by 10"), more shallow (by 2") and more angled (11" wider on each side) than its standard counterpart. This comparison simplifies disparities that Rumford specialists understand in detail.

Prefab components that save them labor-intensive steps are demonstrated in videos (above & below).

Training & Workshops

If you are interested in learning more academically or how to build a Rumford fireplace hands-on, courses and seminars are available. Jim Buckley who writes prolifically on this topic offers a class covering history, style, chimneys, design, codes, construction, performance, seismic issues, green issues, emissions, cost, and marketing.

Contact stone masons or contractors. Check alphabetical listings by state under "The Stone Foundation Directory" or local trades schools and colleges with masonry degrees. 

Your pursuit could quite literally keep the institutional knowledge of Rumford building alive for posterity.

Rumfords Past and Present

These fireplaces were constructed at different intervals either originally (see above) or during renovations. Jefferson's Monticello (Charlottesville, VA) has eight Rumfords. The 1663 Barret-Byam Homestead (Chelmsford, MA) was retrofitted in 1800 with one in every room.

Today National Register of Historic Places narratives and local real estate listings feature them. A draw for a 21st-century-built Craftsman-Adirondack-style residence-for-sale was that: The "great room is anchored by two majestic Rumford fireplaces, resplendent with stones rescued directly from the lake" ("Lady of the Lake," Portland [ME] Monthly: Summertime Guide).

You can discover designs online in image galleries and on home sites. While certain aspects (materials, colors, motifs) coordinate with modern products and tastes, the original Rumford principles have prevailed.

Contemporary Rumford Fireplace

Wood leaning tepee style, within a pair of andirons, placed within a Rumford herringbone firebox, lining a metal prefab, installed in a brick wall.

Wood leaning tepee style, within a pair of andirons, placed within a Rumford herringbone firebox, lining a metal prefab, installed in a brick wall.

Diverse Fireplace Design

The Rumford fireplace is not merely an ornamental structure languishing in historic interiors. Some are contemporary. Others are outdoors even made of cob (earth, sand & straw) and decoratively painted (second video below).

You might unknowingly have a Rumford in your own house.

My mother went to dinner with someone who lives in a late 18th century house and asked if she had a Rumford. The woman replied, "I don't think so." The next day she called to say, "I just asked Andrew [her husband] what kind of fireplace we have in the dining room. He wasn't sure. But the ones in the living and piano rooms have been Rumfordized!"

A fireplace is a pyramid of priorities: well being (safety & sustainability), well working (functionality), and well looking (aesthetics). If you are planning on building or retrofitting one, consider the Count's design for the same reasons he did 200+ years ago.

To snapshot a Rumford fireplace think three S's:

  1. Shallow (depth)
  2. Slanted (sides)
  3. Streamlined (throat for smooth flow).

This article is merely the tip of the iceberg of a fascinating true story on par with the likes of Ben Franklin. I hope we continue researching about and saving the history of Sir Benjamin Thompson Count of Rumford and his inventions. After all, in 1906 author and architect Gillespie aptly stated that he was the "Father of Proper Fireplace Construction."

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Features of Clay Chimney Pots, Venturi Effect, & Chimney Maintenance

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