Which safety device used by miners to detect dangerous gases was invented by Sir Humphry Davy in the nineteenth century?

Introduction / Context:
Working in coal mines was extremely dangerous due to explosive gases such as firedamp. Miners needed a reliable way to detect the presence of such gases without triggering explosions. Sir Humphry Davy, a British chemist, developed a special lamp to address this safety issue. This question asks you to identify which device was invented by him for miners.

Given Data / Assumptions:

• The inventor is Sir Humphry Davy, a chemist and experimental scientist.
• The device improved safety in mines by reducing explosion risk.
• The options include various inventions, some unrelated to mining.
• We assume familiarity with the term Davy lamp from general science reading.

Concept / Approach:
Sir Humphry Davy invented the safety lamp, often called the Davy lamp, for use in coal mines. The lamp uses a metal gauze around the flame to prevent the ignition of surrounding gases. If harmful gas is present, the flame changes appearance, warning miners, but the flame remains enclosed and less likely to cause an explosion. Thus, the safety lamp is the invention attributed to Davy in this context.

Step-by-Step Solution:
Step 1: Recall that Davy was a chemist, so his invention is more likely to involve gases, flames and safety rather than mechanical engines. Step 2: Recognise that the term Davy lamp appears in many descriptions of mining history. Step 3: Notice that safety pin, steam engine and X ray technologies are credited to other inventors. Step 4: Conclude that the safety device invented by Sir Humphry Davy is the safety lamp.

Verification / Alternative check:
Historical accounts of coal mining safety often note the introduction of the Davy lamp as a key milestone. It reduced the number of accidental explosions in mines and became an important symbol of industrial safety. This repeated linking of Davy name with the safety lamp and with mining confirms that option C is correct.

Why Other Options Are Wrong:

• Safety pin: Generally linked with Walter Hunt or later patent holders, not Davy.
• Steam engine: Developed over time by inventors such as Thomas Newcomen and James Watt.
• X ray tube: Related to the work of Wilhelm Roentgen and later experimenters, not to Davy.
• Electric fuse: A separate electrical safety device, not the mine lamp that Davy designed.

Common Pitfalls:
Sometimes students confuse Davy with other industrial inventors and may be tempted to choose the steam engine because it is a well known historical machine. To avoid such confusion, keep clear in your mind that Davy work focused on chemistry and safe lighting in dangerous environments, which points directly to the safety lamp.

Final Answer:
Sir Humphry Davy invented the safety lamp used by miners to detect dangerous gases.