Two things are immediately apparent in this short report from May 18, 1866, 23 years before the formation of the Miners’ Federation of Great Britain, the UK’s first national mine workers union.
First, our reporter noted that 1000 or so miners were killed annually in Britain’s collieries. Second, our reporter added that a number colliery owners weren’t at all bothered by the deaths of miners digging for their profits.
According to the report, The Engineer’s journalists had descended into mines several times, and were ‘painfully struck with the very indifferent light given by the Davy lamp.’
“We feel little doubt that many of these lives are indirectly lost through the bad light by which the men are obliged to work,” said The Engineer. “Working colliers complain of the poor light they are obliged to work by, and more than one have expressed their surprise to us that the lamp has not been improved.”
Plenty of work was being carried out to improve on Sir Humphrey Davy’s lamp, but ‘colliery owners have not given them much encouragement’.
“At the Museum of Practical Geology in Jermyn Street [London], there are more than 20 different specimens of safety lamps, most of which are safer and afford a better light than the Davy,” said The Engineer.
Until 1840 the Davy lamp was used exclusively in mines, but by that time Belgian engineer Mathieu Louis Mueseler had developed an eponymously named lamp that was in widespread use in the pits of his country.
The Davy lamp was designed to provide illumination with a naked flame without causing combustion in the presence of fire-damp, which is any flammable gas found in coal mines, typically coalbed methane.
In practice, the Davy safety lamp did not always offer protection from fire-damp, and ‘its light - which is at no times good - becomes almost totally obscured after being some hours in the pit from the meshes being choked with coal dust.’
“Mueseler’s invention, constructed on the principle of Sir Humphrey Davies lamp, was said to be far free from its disadvantages that it is perfectly safe under all atmospheric combinations, even when its wire network is enlarged or broken; that it gives a light equal to that of two Davy lamps, that it burns less oil, and that it goes out when the flame is brought into contact with carbureted hydrogen, thereby giving warning of danger,” said The Engineer.
It was, however, heavier than the Davy lamp and likely to go out when placed on a slant or carried out of the perpendicular.
“Notwithstanding this fault, the Mueseler lamp, on account of its superior safety qualities, is now generally used in the Belgian collieries, and we may add also in the collieries of the north of France,” said The Engineer.
In Mueseler's lamp’s, the wick-holder and the hook for trimming the wick were generally arranged in the same way as with the Davy lamp, but a thick glass cylinder took up about two fifths of its entire height.
“A conical tube serves as a chimney to conduct outside the products of combustion, and it passes through a diaphragm of wire gauze to which it is fixed,” our reported noted. “The cylinder of wire gauze is furnished at the top with a cap of copper plate, and below with a short cylinder of the same material, which last is made with a horizontal rim, by means of which it can be fixed to the glass cylinder.”
The Engineer continued: “The air required for the combustion passes gradually through the cylinder and the wire gauze, disc or diaphragm, until it reaches the annular space between the chimney and the glass cylinder; coming in contact with the wick, it affects the combustion, rises up the centre of the lamp, and streams through the chimney and the holes of the top, and also through the topmost meshes of the wire cylinder.”
Like its rival predecessor, the flame in Mueseler lamp’s lengthened and extinguished in the presence of fire-damp.
“As the air required for the combustion comes from above, should the fire damp which may get into the case get inflamed, the products of the combustion have not time to escape up the chimney; they partly remain in the cylinder and mix with the fire-damp coming from the outside, so that the flame gets every moment less and less air to feed it,” said The Engineer. “In the meantime the carbonic acid gas collects itself at the bottom of the cylinder and puts out the flame as soon as it gets high enough.”
As noted, the Mueseler lamp was liable to be extinguished when set in a slanting position, and it was also subject to get extinguished in an up current of air, especially when the miner was coming down pit ladders.
“Even with these various disadvantages the Mueseler lamp is undoubtedly preferable to the Davy,” said The Engineer’ “Its construction per se makes it safer; and, above all, its superior light must greatly add to the personal safety of the collier. The majority of the accidents occur through falls of the pit wall; and it must be evident that this danger is increased when the collier is working in a dim and uncertain light.”