.h
section 4原文背景:
Saucer-type Open Grease Lamps
The first type of mine light, the open saucer-type grease lamp, was popular in the 1700s and was often decorated with ornamental figures such as roosters. These figures acted as good luck charms for the miner.
Candles
Later, candles made of hard tallow became a popular source of light within the mines. The candle-holder was adopted for use in the mines as well. It consisted of a 3/8-inch iron rod twisted into a looped handle at one end and a sharpened point at the other. Often there was a hook on the holder and when the point could not be driven into a suitable support, the holder could be hung from any overhang or protrusion in the mine.
Safety Lamps
The man who made the real breakthrough in this area was Sir Humphry Davy when he invented what is known as the Davy Lamp or a gauze-enclosed lamp. Although gauze alone could not guarantee that the flame would not come into contact with gases outside the screen, Sir Davy reasoned that a metal mesh would cool down the flame before it came into contact with any fire damp. These gases explode at certain temperatures but will extinguish a flame that is cooler.
To prevent miners from opening their safety lamp underground, considerable attention was paid to locks. Most safety lamps were equipped with a padlock, keyed setscrews, melted soft-metal locking inserts or magnetic spring-loaded latches.
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