Where can mercurial barometers and thermometers be carried?

• A. As checked baggage only
• B. As carry-on baggage only
• C. Only in the cargo area
• D. They cannot be carried at all

Answer: (B)

Mercurial barometers and thermometers are allowed to be carried in the cabin of an aircraft as part of carry-on baggage because they are considered necessary instruments for specific applications, such as meteorology or scientific research. These items contain mercury, which is classified as a hazardous material, but special allowances are made for such measuring instruments due to their importance and the relatively small quantities involved.

Carrying them in the cabin ensures that they are handled with care and remains in the oversight of the owner, thereby reducing the risk associated with mercury spills or breakage during transport. This allows travelers who require such instruments for their work or research purposes to transport them safely without the heightened restrictions that apply to more hazardous materials.