It occurs during the week of the shortest day and longest night of the year in the northern hemisphere, when ancient holy men and women lit “yule logs” to push back the darkness and bring back the light of summer. As Henry Bourne wrote in 1725: “For as both December and January were called Guili or Yule, upon Account of the Sun’s Returning, and the Increase of the Days; so, I am apt to believe, the Log has had the Name of the Yule-Log, from its being burnt as an Emblem of the returning Sun, and the Increase of its...