Brass Theodolite Key Chain 5"

Basically a telescope mounted on two movable planes, one horizontal and one vertical, the theodolite is an important historical tool used both on land and at sea. Mounted on a tripod the theodolite on this nautical keychain has been a common tool since the late 18^th century. Prior to 1512, and the invention of the polimetrum, separate instruments were necessary to measure horizontal and vertical angles in surveying. The first mention of the theodolite was by published in 1571, though at that point production was limited. Toward the end of the 1700s the modern instrument was developed, as was the ability to mass produce these tools. Reproduced on these nautical keychains the first available theodolites were used by both the British and American navies as well as many private seafaring vessels. The U.S. Navy used a theodolite, like the one on this nautical keychain, to take the first accurate surveys of North American harbors and coastlines. Theodolites were also commonly used out at sea, charting the many tiny islands that dot the vast expanses of the Atlantic. Particularly of use in creating treasure maps, pirates used the tool featured on this nautical keychain to plot maps to hidden bounty. These solid brass keyrings, produced from the same material as many early theodolites, represent an important tool in the history of early modern sailing and navigation, and provide a wonderful reminder to the nautical enthusiast.