The vertical component of the Earth's magnetic field causes induced magnetism in vertical soft iron. This changes with latitude. What corrects for this coefficient of the deviation?

Correct Answer: Option B — The Flinders bar

The Flinders bar is a vertical soft iron rod placed on the binnacle to compensate for the vertical component of the Earth's magnetic field. Because this vertical component changes as the vessel moves between latitudes, the Flinders bar is essential for correcting induced magnetism in vertical soft iron.