dip circle การใช้

• Early dip circles were not accurate and gave poor results.
• Improvements which made the dip circle a practical aid for polar navigation were made by Robert Were Fox FRS, who developed in the 1830s the first dip circle that could be used on board a moving ship.
• Improvements which made the dip circle a practical aid for polar navigation were made by Robert Were Fox FRS, who developed in the 1830s the first dip circle that could be used on board a moving ship.