Time TravelBy Chris Landers
Published: October/November 2013
The Smithsonian explores the challenges of getting from here to there. It's about ... time! Boaters, reliant on the extraordinary navigation aids of the modern world, will find this new exhibit fascinating.
Photo: Folger Shakespeare Library
The Mariner's Mirrour, by Dutch author Lucas J. Waghenaer, was the first ever
"Sea Atlas." Look carefully at its detailed images, and you'll discover
a treasure trove of 15th-century navigation instruments.
To get to the new "Time and Navigation" exhibit at the Smithsonian Institution in Washington, D.C., you must first navigate to the National Air and Space Museum. Go up the escalator, pass the excited throngs of high-fiving young fellow navigators on school trips, and choose the door between the engineering model of the spacecraft Clementine and a Tomahawk cruise missile. Walk through that door, and you enter a world of sea and air navigation through time, a compelling interactive exhibit of the people, voyages, and most importantly the instruments that made your remarkable journey possible.
William Cranch Bond, a 23-year-old Boston clockmaker, made this chronometer during the War of 1812. It was the first American-made marine timekeeper taken to sea.
This sextant, invented in the 18th century by British mathematical instrument makers, permitted mariners to find their position better than ever before. It became the most essential instrument for celestial navigation, used to find the angle of a celestial body above the horizon.
It's not that you need to use a lead line or astrolabe to get here (frankly, it would be strange if you did), but beyond those archaic instruments, inside the exhibit entrance lies one of our most important tools, and one that has been improved upon to the point where almost all of us, navigators and sign followers alike, carry it with us — the chronometer. Yes, the humble clock is the thread that runs through the entire exhibit, which covers the period from the earliest attempts to survey a hostile ocean, right up to the latest generation of GPS. Along the way, we learn about Lt. Charles Wilkes, USN, who led the United States Exploring Expedition that circumnavigated the globe from 1838 to 1842. Wilkes brought back treasures from the uncharted Pacific — a display case is filled with them, from a Malay dagger to a Fijian throwing club — and his collection formed the basis for the Smithsonian Institution itself. (Wilkes' accomplishments likely would have secured him a better place in history if the Navy hadn't court-martialed him twice, having found him guilty of disobeying orders and inordinately harsh treatment of his men.)
Photo: Smithsonian, Library of Congress
A coastal navigation chart from 1633 made by medieval European mariners,
based on their measurements, and embellished with the remarkable images
that had impressed them from their voyages.
Wilkes spent a small fortune on navigation equipment to outfit the expedition. Some of it is on display, but as the exhibit turns the corner, most of Wilkes' beautiful marine chronometers and other instruments, though sophisticated for their time, have been rendered obsolete by the 20th century. In one corner, as the stentorian voice of an old Coast Guard film explains the wonders of LORAN, a visitor pauses to explain to her sons, "When I was your age, we had wind-up watches." And indeed we did, for centuries, until quartz vibrations and atomic clocks took their place. Meanwhile, as you navigate this part of the exhibit, star charts and sextants became more and more advanced until our navigation instruments themselves appeared in space. Here satellites strung from the ceiling "beam" coordinate back to terrestrial devices of decreasing size. (The navigation equipment of the submarine USS Alabama, outfitted in 1983, looks like a refrigerator repair store with a typewriter bolted on, compared to the svelte and powerful handheld GPS unit we see a few yards and years down the timeline.)
The evolution of the timepiece has driven the history of navigation — from the hourglass and sundial to the waterproof, barometer-equipped wristwatch.
From taking sun shots to navigating by stars, the sextant was a mainstay of nautical life for centuries. Now we steer by a man-made set of celestial bodies — Global Positioning Satellites.
The old string-and-weight lead line may seem like an artifact from the distant past, but the U.S. Coast Survey used them until 1923, and even then, they used it to check the accuracy of their newfangled echo sounders.
Back at the door, having circumnavigated the story of several centuries of navigation, visitors find themselves between two extremes. On the right stand the knot-logs and sandbags of our earliest intrepid explorers. On the left, a small Plexiglas display case contains a smartphone, a reminder that knowing exactly where we stand, so to speak, is now within the grasp of anyone. Finding your way home should be easy.
Time and Navigation: The Untold Story of Getting From Here To There is now part of the permanent exhibitions at the Smithsonian Air and Space Museum in Washington, D.C. For more about the exhibit, there's a companion website at http://timeandnavigation.si.edu
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To determine position in space, Apollo astronauts located a specific star using a single-power, wide-field telescope and then took a fix using ... a sextant! While this instrument may not look like a traditional sextant, the basic procedure is descended from centuries-old methods used by navigators at sea and in the air.
Capt. L. C. Bygrave developed this slide rule for celestial navigation shortly after World War I, speeding up celestial computations.