Table 6 Lux values and radiative heat measurements for the 0 °C, 35 kg fuel, 1-m diameter fire experiments. Average and peak values are reported at 1- and 2-m intervals from the fire with duration in minutes in brackets

From: Assessing the Function of Palaeolithic Hearths: Experiments on Intensity of Luminosity and Radiative Heat Outputs from Different Fuel Sources

Fuel type, 0 to 3 °C Species Lux av and duration 1 m Peak lux and duration 1 m Lux av and duration 2 m Peak lux and duration 2 m Radiative heat av and duration 1 m Peak radiative heat and duration 1 m Radiative heat av and duration 2 m Peak radiative heat and duration 2 m
Fresh bone Roe deer (Capreolus capreolus) 5.8, 1–8.8, (300) 7.3, 6.1–8.8, (200) NA NA 21, 4.1–32, (310) 24, 17–32, (230) NA NA
Softwood Spruce (Picea abies) 20, 1.8–39, (80) 33, 26–39, (30) 12, 3–16, (50) 14, 13–16, (30) 25, 2.1–43.7, (110) 40, 28–47, (50) 11, 3–18, (80) 17.6, 16.4–18.6, (20)
Softwood Alder (Alnus glutinosa) 5.7, 1.1–9.6, (70) 8.4, 7.4–9.6, (30) 1.5, 1–2.6, (30) NA 12, 4.2–19.4, (60) 18.7, 17–19, (30) NA NA
Softwood Pine (Pinus sylvestris) 17, 1–32, (140) 29, 27–32, (40) 5.4, 1–9, (100) 8, 7.3–9.1, (30) 27, 3–42, (170) 36, 28–42, (100) 8.8, 2.4–2.6, (140) 11, 10–12.6, (70)
Softwood Larch (Larix decidua) 18, 1.2–37, (140) 30, 25–37, (40) 6, 1–12.9, (120) 10, 7–12.9, (50) 25,2–45, (160) 36, 26–45, (60) 9.7, 2–15.3, (140) 14, 12–15.3, (40)
Hardwood Oak (Quercus robur) 4.5, 1–7.9, (150) 6.6, 5.2–7.9, (70) 1.4, 1–2.8, (80) NA 19, 3–32, (200) 29, 27–32, (70) 6.4, 3–9.2, (150) 8, 7.4–9.2, (70)
Hardwood Beech (Fagus sylvatica) 21, 1–41, (120) 35, 24–41, (50) 10.2, 1.3–17.6, (90) 16, 14.2–17.6, (30) 21, 3.6–36, (150) 31, 25–36, (60) 9.4, 3.2–15.1, (110) 14, 13.2–15.1 (40)
Hardwood Ash (Fraxinus excelsior) 24, 1.1–70.1 (90) 64, 60–70, (20) 12, (60) 25, 21–28, (20) 25, 3.1–58, (150) 52, 49–58, (20) 9.3, 5–15, (110) NA
Hardwood Silver Birch (Betula pendula) 30, 1–56, (90) 52, 42–56, (40) 15, 1.4–32, (70) 24, 20–32, (30) 29, 4.2–59, (130) 49, 36–59, (50) 12, 3–18.6, (120) 17, 16–18.6, (50)