🔍 Key Concepts

• Difference between dry-bulb and wet-bulb thermometers • What information is needed to find relative humidity • Common instruments used in celestial navigation vs. weather observation

💭 Think About

• Think about where you would physically see or use a sling psychrometer on a vessel and for what purpose • Which option involves using two thermometers that you swing through the air? • Ask yourself which choice is clearly associated with navigation (position finding) and which is associated with atmospheric conditions

✅ Before You Answer

• Verify which option relates to measuring moisture content in the air • Eliminate the choice that is used with a sextant, almanac, and sight reduction tables • Eliminate any option that is obviously related to weights, densities, or cargo handling gear rather than air conditions