William Grainge
... that the regular nature walks taken by historian and naturalist William Grainge averaged 24 miles (39 km)?
... that the regular nature walks taken by <a href="./Historian" id="mwAtg" rel="mw:WikiLink" title="Historian">historian</a> and <a href="./Natural_history" id="mwAtk" rel="mw:WikiLink" title="Natural history">naturalist</a> <b id="mwAto"><a href="./William_Grainge" id="mwAts" rel="mw:WikiLink" title="William Grainge">William Grainge</a></b> averaged <span about="#mwt48" data-mw='{"parts":[{"template":{"target":{"wt":"convert","href":"./Template:Convert"},"params":{"1":{"wt":"24"},"2":{"wt":"mi"},"3":{"wt":"km"}},"i":0}}]}' id="mwAtw" typeof="mw:Transclusion">24 miles (39</span><span about="#mwt48" typeof="mw:Entity"> </span><span about="#mwt48">km)</span>?