Yet from prehistoric times, fire's virtues (as a means of cooking as well as protection from the cold and from wild animals) made it worth the effort — and fanned a burning desire to harness and safely contain it indoors.
Besides the challenges of producing a flame and finding fuel, the greatest strike against indoor fires was safety. Primitive shelters (caves, huts, teepees) did offer a few fire-friendly features: Roof openings (some by design and some not) provided an escape route for smoke; gaps in the walls allowed air intake for venting; and dirt floors offered a noncombustible surround. But as dwellings became more sophisticated, they required better ways to contain flames, control smoke and preserve indoor air quality.
The development of the chimney allowed fireplaces to move from the centers of rooms to outer walls and upper floors. Depending on their height, shape and diameter, some chimneys expelled smoke better than others. Original designs vented horizontally (and extremely poorly); later vertical chimneys maximized the natural tendency of smoke to rise upward and funneled it outside. Observing various differences in performance, architects of the 1500s began to study the structural and scientific aspects of fireplace design.
Other functional developments followed. In 1678 English inventor Prince Rupert created a fire grate that allowed airflow beneath the fuel (wood or coal) for better combustion. In the 1700s Benjamin Franklin, upon observing the mechanics of radiant and convection heat, created a freestanding cast-iron stove. The iron retained and radiated heat even after the flame was gone, and a built-in vent at the top of the chamber allowed heated air to circulate into the room. Modern versions of the Franklin stove are still in use today.
The 1790s saw one of the most profound innovations in fireplaces: the Rumford fireplace, invented by Sir Benjamin Thompson (later known as Count Rumford). His understanding of airflow dynamics and heat transfer shaped an efficient fireplace design that has endured as the model for modern fireplaces (see photo above).
With the functional aspects of fireplaces settled, attention turned to aesthetics. During the Victorian era, a fireplace was valued as much for its decorative flair as for the heat it produced. Ornate mantels and surrounds made of exotic woods, marble, stone and tiles took center stage. A hearth's charm and beauty made it a popular gathering spot (with or without the flame).
The convenience of central heating introduced in the 20th century did not dampen appreciation for the fireplace. Gas-fueled and wood-burning units have become standard fare in today's homes – regardless of climate or culture. Our inborn attraction to the light, movement and color of a dancing flame is just one reason that the fireplace is (and always will be) an alluring retreat for family and friends.CAPTION
Angled sides, a tall, shallow box and a rounded flue enabled the 18th century Rumford fireplace (photo above) to burn efficiently and better radiate heat into the room. Its creator, Count Rumford, designed it to conserve fuel, deliver more heat and ensure good air quality, goals that resonate today.