Lighting the Mine
In tin mines, there is usually no danger from explosive gases like there is in coal mines. Miners used to smoke clay pipes underground in the past and in the modern mine cigarette smoking was common. In very early times, miners used small oil lamps. By the 18th century, tallow [animal fat] candles were normally used. Candles were used up to the 20th century. By mid-century, the acetylene or carbide lamp was used by most miners.
In very early times, miners used small oil lamps. The earliest ones were made of clay.
By the 18th century, tallow candles were used as the main source of light underground. Tallow is a hard creamy coloured fat from animals, the best quality for candles coming from sheep. It is much softer than paraffin wax or beeswax. Beeswax candles have been in use from very early times but were very expensive and therefore used only by the church and the rich, never by miners. When lit, tallow candles can be quite smelly producing a lot of smoke. Candles made from pig’s fat tallow were said to have a very unpleasant smell. It was known for miners in poorly ventilated areas to work in the dark rather than breathe in the smoke which would build up from their candles.
The wicks were made from many twisted threads of flax, cotton, or hemp. Unlike our modern wicks they had to be trimmed to keep the candle from excessive smoking, or from getting too hot, which could cause guttering - melted fat streaming down the sides.
The miners used wet clay to attach their candles either to their hats, called tulls, or to the rock wall where they were working. They also had candle holders with spikes on them that could be driven into the mine walls.
The candles were made by dipping the wicks into melted tallow, time and time again to build up layers and later on by using molds. The dipping method led to the candles being called dips and to them coming in bunches of 2 with the wick from one being joined to the other. This loop made a useful way for miners to carry their candles by looping them over their buttons..
A tallow candle was not just for light. It was also used to tell the time. The time it took to burn a candle down becoming a unit of time. 4 candles (taking about 2 hours to burn down each) equaled a day’s work (or about 8 hours).
Tallow candles were also used to tell the quality of the air. The level of oxygen required in the air for a flame to burn is slightly more that is required for a human to breath. If you could not keep your candle alight it was time to seek out a better ventilated area. This fact also led to miners putting out their candles, so as to not use up the air.
Unfortunately, some of the worst off miners were known to eat their candles as a source of animal fat where littlecould be provided in their diet. For this reason mine owners often poisoned their candles- making them inedible .
Tallow Candles were replaced by paraffin candles (discovered in 1850) and these continued in use until the early part of the 20th Century when they were slowly replaced by carbide lamps.
Fire was a danger in dry mines where a lot of timber was used.
Carbide lamps produced light by burning acetylene gas. By mid 19th century, the acetylene or carbide lamp was used by most miners, although Geevor has many photographs of candles still being used.
The carbide lamp was developed in America in the early 20th century. Water drips from an upper tank onto calcium carbide in the lower tank. This produces acetylene, a gas which burns with an intense white flame. The dripping rate could be adjusted to change the size of the flame which would change the brightness of the lamp.
The lamps produced a bright light but had to be regularly re-filled with calcium carbide and water. Miners carried a tin of spare calcium carbide chunks in their pockets and it was said that you could tell a miner coming by the sound of the tin rattling.
These lamps were in use at Geevor as late as 1960 when they were replaced with battery powered lamps.
A quick way to tell that all the miners were safely back was to check along the rows of charging lights to see if any were missing. Each numbered lamp could quickly be matched to an individual and the location he was working in.
The mine was a place of clear roles and hierarchy and this was reflected in the colour coding of the lamps. Yellow, red and blue were for.
Humphry Davy Safety Light
This was invented in 1815 by Sir Humphry Davy. He was a Penzance man, who became a famous inventor and chemist. It is a common misconception that his lamp was used in tin mines in Cornwall. This is not quite true, It was created for use in coal mines where the explosive gases present (called firedamp) caused many devastating disasters. Davy’s lamp enclosed the lamp flame inside a mesh gauze. Any combustion of firedamp was contained within the mesh.
The lamp was heavy and not as bright as a candle so not used for lighting in Cornish mines. However, the lamp could also be used to test for the presence of different gases by examining the flame and was sometimes used in tin mines for this purpose.
Humphry Davy is commemorated in his home town of Penzance with a statue and the local school is named after him.
Certain important areas underground were lit with electric lights. These included the shaft stations and pumping stations, as well as the battery charging bays for the locos. Some grizzlys were also lit. Often the walls of these areas were also painted white to add further brightness.