🔍 Key Concepts

• Difference between permanent and induced magnetism in a steel ship • Role of different correctors on a standard magnetic compass: Kelvin spheres, heeling magnet, and Flinders bar • How the ship’s heading and heel affect the compass

💭 Think About

• Ask yourself: which type of magnetism changes with the ship’s latitude and vertical magnetic field of the earth? • Which correctors are used for soft iron (temporary/induced magnetism) versus hard iron (permanent magnetism)? • Which corrector specifically deals with errors that appear when the ship heels or when moving to areas of different magnetic dip?

✅ Before You Answer

• Identify which answer choices refer to permanent magnetism and which refer to induced (temporary) magnetism • Decide whether the Flinders bar is made to correct horizontal or vertical components of the ship’s magnetism • Recall that the Flinders bar is a soft iron bar placed vertically near the compass—what kind of magnetism would that most logically influence?