Old Black
...that in the 1850s Arnold Guyot measured the elevation of Old Black in the Great Smoky Mountains to within 3 feet (1 m) of the modern value?
...that in the 1850s <a class="mw-redirect" href="./Arnold_Guyot" id="mwAQc" rel="mw:WikiLink" title="Arnold Guyot">Arnold Guyot</a> measured the elevation of <b id="mwAQg"><a href="./Old_Black_(Great_Smoky_Mountains)" id="mwAQk" rel="mw:WikiLink" title="Old Black (Great Smoky Mountains)">Old Black</a></b> in the <a href="./Great_Smoky_Mountains" id="mwAQo" rel="mw:WikiLink" title="Great Smoky Mountains">Great Smoky Mountains</a> to within 3 feet (1 m) of the modern value?