574 Gasu Bakuhatsu[Gas Explosions in the Mid-Meiji Era]

The disaster (hijo) caused by the gas explosion in Hokoku Coal Pit greatly jolted miners in the Chikuho region and threw them into total shock. It occurred on June 15, 1899 and was the first great disaster in this region, killing 210 miners. Gas explosions also occurred in K Coal Pit at that time and two or three miners per month were burnt in them. Only sakiyamas (normally male hewers) were injured by explosions of firedamp around their coalfaces. Each single coalface called an itcho kiriha at that time was allotted to a hewer and kept untouched until the next day after he finished working on it. During the vacant time, methane gas accumulated in the end (kirizume) of ascending single coalfaces. When hewers reached the coalfaces in the early morning and lit their lamps, the gas exploded. Later, lamps were replaced with safety lanterns. However, they were not like the one shown in the insets. They used rapeseed oil and each of them had a chimney composed of a glass skirt and a Clanny-type metal-gauze barrel.

Descriptions of the Safety Lantern in the Insets
Inset (1) (Bottom)
Safety Lantern in the Latter Half of the Meiji Era
It had a screw to adjust the flame on its bottom. It was ignited with a flint and steel installed in it. When the flame in the safety lantern was as small as a grain of millet near the bottom of a level, it had to be kept as it was.
Inset (2) (Middle)
Gas Check with a Safety Lantern without Knowing the Percentage of the Firedamp
The flame lengthened vertically when the safety lantern was lifted up in the middle of the space between the roof and bottom of a level.
Inset (3) (Top)
The standardizing box was not used in small and middle-scale coal pits.
If the chimney was filled with fire when the lantern was lifted up near the roof, it should be calmly and slowly lowered.

Text at the Top Middle
When firedamp exploded, a great blast blew all the lamps out at the same time, which were used by the miners working underground.

Text at the Bottom Left
The air around coalfaces with a lot of firedamp looked clear in the morning, but the gas caused tears to come out of hewers’ eyes. The air smelled like burned iron (or ohaguro [the tooth-dye]). The firedamp naturally went away if miners worked there and the air was stirred. However, it accumulated around the coalfaces again if they were not mined for a while.
It was said that if a gas explosion occurred once underground, the next one became greater. It was said that the fire blew back again after every explosion. It was also said that in each underground explosion there was no fire in the space between the air about 15 centimeters high and the bottom of the explosion site. Miners who underwent gas explosions said that inhaling burning gas was more fatal than being burned by it.
Miners checked their own safety lantern themselves.