National Air and Space Museum’s “Time and Navigation: The Untold Story of Getting from Here to There” exhibit – Navigating at Sea

The first section visitors will see is Navigating at Sea. This section explores the tools navigators used to cross the sea long before the time of GPS. Visitors will learn how navigators relied on chronometers and sextants to find their way across vast oceans. 

 

This section includes a mariner’s astrolabe dating from 1602. Astrolabes were instrument used from the middle ages until the 18th century to observe the position and determine the altitude of the Sun or other astronomical object. Astrolabes were replaced by the sextant. 

 

Visitors can also see a Ramsden sextant and dividing engine (used in the manufacture of sextants several chronometers and a model of Galileo’s pendulum clock.

 

Also on display is the earliest sea-going marine chronograph made in the United States, produced by Bostonian William Cranch Bond during the War of 1812. Chronographs greatly aided navigation by providing far more precise time keeping accuracy than previously attainable.  

 

Visitors can also learn how a sextant is used and even participate in an interactive exhibit allowing them to use a sextant to navigate with the stars.