Houses in prehistoric sites in Orkney where the early farmers once lived, as at Skara Brae, show where the hearth was placed in the main living area, usually at the centre. Questions are often raised about how the inhabitants coped with the smoke emitted from the fires. This practice of a central hearth continued for thousands of years and at Kirbuster Farm Museum in Orkney we can see how the smoke rose up into the roof space and out through a gap.

Then a back stop was added and finally the hearth was moved to the end of the hoose with a chimney.

New research from Tel Aviv University has been revealing that the earliest humans were working out where the best place was to situate the hearth – to provide warmth and meal preparation without the disastrous effects of smoke inhalation.

In a first-of-its kind study, the researchers developed a software-based smoke dispersal simulation model and applied it to a known prehistoric site. They discovered that the early humans who occupied the cave had placed their hearth at the optimal location – enabling maximum utilization of the fire for their activities and needs while exposing them to a minimal amount of smoke.

Researcher Yafit Kedar explained:

“One focal issue in the debate is the location of hearths in caves occupied by early humans for long periods of time. Multilayered hearths have been found in many caves, indicating that fires had been lit at the same spot over many years.

“In previous studies, using a software-based model of air circulation in caves, along with a simulator of smoke dispersal in a closed space, we found that the optimal location for minimal smoke exposure in the winter was at the back of the cave. The least favorable location was the cave’s entrance.

 “According to our model, based on previous studies, placing the hearth at the back of the cave would have reduced smoke density to a minimum, allowing the smoke to circulate out of the cave right next to the ceiling. But in the archaeological layers we examined, the hearth was located at the center of the cave. We tried to understand why the occupants had chosen this spot, and whether smoke dispersal had been a significant consideration in the cave’s spatial division into activity areas.”

Early humans needed a balance – a hearth close to which they could work, cook, eat, sleep, get together, warm themselves, etc. while exposed to a minimum amount of smoke. Ultimately, when all needs are taken into consideration – daily activities vs. the damages of smoke exposure – the occupants placed their hearth at the optimal spot in the cave.

 Prof. Ran Barkai added:

“Our study shows that early humans were able, with no sensors or simulators, to choose the perfect location for their hearth and manage the cave’s space as early as 170,000 years ago – long before the advent of modern humans in Europe.

“This ability reflects ingenuity, experience, and planned action, as well as awareness of the health damage caused by smoke exposure. In addition, the simulation model we developed can assist archaeologists excavating new sites, enabling them to look for hearths and activity areas at their optimal locations.”

The influence of smoke density on hearth location and activity areas at Lower Paleolithic Lazaret Cave, France, is published in the journal Nature