Two hundred years ago, tomorrow, Sir Humphrey Davy tested his mine safety lamp in a working coal mine. Davy had invented and perfected his safety lamp in the autumn 1815. Was this first test a success? More importantly, was the design of the safety lamp really Davy’s? Today, Davy gets the lion’s share of the credit for inventing this special lamp which was intended to light the way for coal miner’s without putting them at risk of an explosion. But in actual fact, he was just one inventor who devoted time and talent to the resolution of this problem. Therefore, through 1816, a controversy played out in private letters and in the press as to who was the "real" inventor of the mine safety lamp.
Davy’s safety lamp, a taste of the controversy which followed its introduction and its actual impact . . .
Though it may seem a bit odd to us today, from the mid-fifteenth century to about the mid-nineteenth century, coal miners used the term "damp" to refer to the various noxious, unbreathable vapors which were found in the mines in which they worked. There were several different types of damps and all of them were dangerous. Some simply clogged the lungs, while others were also toxic, and a few were flammable and/or explosive. The flammable and explosive damps made working in a mine which was lit by an open candle flame extremely dangerous.
One of those who took an interest in the dangers of damps in coal mines was the scientist, Sir Humphrey Davy. During his own study of various gasses, he was injured while running an experiment in his laboratory which damaged his eyesight. In 1815, Sir Humphrey, his wife and Michael Faraday were travelling in Europe when news reached them that spring of Napoleon’s escape from exile on the island of Elba. Realizing that the Continent was likely to become a battleground once again, Davy and his party soon returned to Britain.
Shortly before Davy had left for Europe, in May of 1812, there was a devastating disaster at the Felling Colliery in County Durham which resulted in the deaths of nearly one hundred miners. Though the cause of that explosion has never been definitively determined, it was generally believed to have been caused by a miner’s light igniting flammable damps. Several different inventors across Great Britain began working on lamps which could be used safely in the tunnels of coal mines. In the fall of 1815, when Davy returned to England, the Rector of Bishopwearmouth, whose parish was located in coal country, asked Sir Humphrey to find a way by which to light coal mines safely. Davy was aware of at least a few of the other inventors working on lamp designs and traveled the country to view their work.
One of those inventors was William Reid Clanny, an Irish-born doctor who was living in the Durham area. In 1813, Clanny presented a paper to the Royal Society outlining his design for a safety lamp. This lamp consisted of a candle in a glass cylinder set between two chambers containing water. A bellows was used to force air through the water, thus filtering out the mine damps before they could come in contact with the flame of the candle. This lamp was heavy, bulky and hard to use. Over the course of the next couple of years, Clanny worked to reduce the size and weight of his lamp design. He successfully tested his redesigned lamp at Herrington Mill. When Davy traveled to the Durham area, in October of 1815, Clanny loaned him the prototype of his redesigned lamp for a day.
Another inventor who turned his talents to designing a lamp which could be used safely in coal mines was the self-taught engineer, George Stephenson. Despite the fact that he was not professionally trained, by a system of trial and error, Stephenson developed a safety lamp design which consisted of a metal cylinder perforated with tiny holes set within in an outer glass cylinder. This system allowed oxygen to feed the flame of the lamp but prevented any flame from escaping the pair of cylinders. A practical man of the middle class, with no connection to the Royal Society, Stephenson wrote no papers on his work. Rather, he tested a prototype of his safety lamp in the tunnels of the Killingworth Colliery. He went down into the mine with two men who volunteered to act as his witnesses. He lit the lamp and placed it in front of a fissure from which he knew firedamp was escaping. The lamp remained lit, but the flame did not ignite any of the flammable gas in the tunnel.
As a trained scientist, Davy acquired numerous samples of various mine damps, then closely studied their properties in his laboratory over a period of several weeks in the autumn of 1815. Based on the results those studies, he designed a lamp which he believed would safely remain lit without igniting any of the gasses or vapors which might be flowing through a mine tunnel. Davy’s lamp design consisted of a cylinder of what he called "iron gauze," a fine metal mesh, very like a modern window screen, which surrounded the flame of the lamp. The mesh allowed air to carry oxygen to maintain the flame of the lamp, but the holes in the mesh were too small to allow any flame to escape the confines of the mesh cylinder.
Sir Humphrey did not stop with a lamp which would not ignite mine damps. He also included a system by which his lamp could test for the presence of dangerous vapors. Flammable gasses would cause the flame of his lamp to burn with a blue tinge, while gasses which posed a threat of asphyxiation would extinguish the flame. Thus, miners were much less likely to be killed by an explosion of mine gas, while the latter test would give miners enough warning to evacuate any part of the mine filled with asphyxiating gasses before they could die of suffocation.
On 9 November 1815, Sir Humphrey Davy presented a paper on his new safety lamp to the Royal Society. His paper was very well-received by the members of the Society. On Tuesday, 9 January 1816, Davy tested a prototype of his safety lamp in the tunnels of the Hebburn Colliery, a working coal mine. The new lamp performed well during this publicized test and Davy’s design was lauded by many. George Stephenson had carried out a much less public test of his safety lamp in the Killingworth Colliery only a few days before Davy had presented his paper to the Royal Society in November of 1815. The success of his lamp was known only to a small circle of his friends and acquaintances.
Though Davy and Stephenson had been working independently, they had each come up with a similar design for their safety lamps. Initially, Davy was accused of appropriating Stephenson’s design, but later, the less well-educated Stephenson, who had few social connections and spoke with a thick Northumberland accent, was accused of cribbing Davy’s work. Though both designs had many small differences, their main principle was similar enough to support accusations of borrowing or outright stealing on the part of both inventors.
This controversy raged for over a year, first in a series of private letters between scientists and others interested in the new lamps. Then it found its way into journal articles and eventually, even some newspapers. William Clanny’s lamp design was pulled into the controversy for a time, early on. But even though Davy had closely examined the prototype of Clanny’s lamp in the fall of 1815, the design of that lamp was so very different from either Davy’s or Stephenson’s lamps that it was not long before the issue was focused solely on Davy and Stephenson. For a time, pressure was put on the more obscure and middle-class Stephenson to admit that his lamp was really based on Davy’s design. He refused and maintained that his lamp was constructed to his own original design. Davy even bought a few of Stephenson’s lamp in order to show they were not as effective as those he had designed, but was unable to do so.
Davy deliberately did not patent his design for his safety lamp, in order to be sure it would be readily available to coal miners. During the Regency, as had been the case for centuries, each miner was responsible for supplying his own light while he worked in the mine. Therefore, it was not the mine owners, but the miners themselves who purchased the lamps which lit their way in the tunnels. Though it is likely that the safety lamp did save a number of lives after its introduction, it may well have led to even more mine accidents which took the lives or limbs of many miners. The light from these safety lamps was not particularly bright, which sometimes made it difficult for miners to see clearly as they were working in a dark tunnel. A number of accidents occurred in the dim light.
The safety lamp was no longer safe if even a single wire of the mesh cylinder rusted away or was broken, as it would create a hole large enough to release a flame which could ignite flammable damps in the mine. Since each miner was responsible for purchasing and maintaining their safety lamps, there was no central oversight of the condition of the safety lamps used in the mines. Should a miner not notice damage to the mesh of his lamp, or be unable to afford a replacement, he might carry an unsafe lamp into the tunnels of the mine in which he worked. Such a lamp could result in the unexpected ignition of flammable damps.
The introduction of the safety lamp also inadvertently led to more accidents since it became an excuse for mine owners to open up areas of their mines which had been closed due to safety concerns such as flammable, toxic or asphyxiating damps. The installation of ventilating systems which would have extracted the bulk of the dangerous damps was considered to be too expensive by most mine owners. Instead, they considered the safety lamps used by their employees to be sufficient protection when they worked in the mine tunnels and few mine owners invested in better ventilation systems.
Though none of the early problems with the first safety lamps was resolved until the last decades of the nineteenth century, the test of his safety lamp prototype two hundred years ago, tomorrow, by Sir Humphrey Davy still offered coal miners better protection while they worked than they had ever had before. His safety lamp was in use by many coal miners long before the end of 1816.