Not talking about open pit mines, but deep mine shafts such as this one. When miners are deep enough, they’ll eventually need to rely on a source of light other than the sun.
However, I imagine that it would be difficult to maintain any premodern lighting source while inside a mine shaft. A rushlight seems like the most obvious to use, but would there be enough oxygen in a deep mineshaft to sustain a small flame like that?
And if a larger flame is used, such as a long torch or wood fire, I imagine it would be too hot for the workers to mine comfortably.
With all that being said, was light a limiting factor in how deep a mine could be?
Thank you!
Romans mines were simply lit using oil-lamps. Primary evidence would suggest that this is how it was done.
Pliny (Natural History. 33.70) states that:
The mountains are allowed out by means of galleries driven for long distances by the light of lamps. The lamps also measure the periods of work, since the miners do not see daylight for many months.
There is also a relief known as the Linares Bas-Relief which depicts which contains one man who is holding a lamp (I tried finding a photo but the availability online is poor).
Speaking from the perspective of Romans mines, a factor of lighting was not really a limiting factor in terms of how deep a mine could be given that there were more significant issues which would be a problem way before light.
With underground mining, you had to extract the ore via shafts, galleries, and tunnels which itself created problems such as preventing the collapse of said tunnels firstly, followed by issues such as ventilation or drainage.
There is plenty of source material as well that depicts such issues:
Pliny (Natural History. 31.49)
When well shafts have been sunk deep, fumes of sulphur or alum rush up to meet the diggers and kill them.
Strabo (Geography. 12.3.40) provides a similar description as Pliny regarding sulphur with further information:
For, in addition to the anguish of the work, they say that the air in the mines is both deadly and hard to bear because of the disagreeable odour of the ore, so the men are quick to die. In addition, they say that often the mine is abandoned because of its unprofitable nature, since there are more than 200 workers but they are continually consumed by sickness and death.
As you can see, lighting was not really an issue because they had oil lamps - the main issues they faced were ones of a more technical nature, of course which they did have solutions too as well.
If you are more interested in Roman mines, the go to book really is:
Hirt, A.M. (2010), Imperial mines and quarries in the Roman World, Oxford.
