Spedding mill illumination device - photo

[jimfols]

Charles Spedding came up with the steel mill which consisted of a steel disk, that the miner rotated at high speed. The miner would then press a flint against the spinning steel disc producing a stream of sparks which the other miners would work from. As you can imagine, this method supplied the miner with a minimum of light for a lot of effort usually provided by a young boy. Worse than this was that the sparks produced could still ignite methane, as was discovered in 1785 with an explosion at Wallsend Colliery. One miner, John Selkirk, was killed, but amazingly, the miner who was operating the Spedding Mill survived and provided the evidence that the ignition source for the methane explosion was the Spedding Mill he was operating at the time.

From here: https://www.hsimagazine.com/article/...%20work%20from.