so at twilight you may walk safely over the swallowing earth

Work's been intense, but I took a break and met wakanomori for lunch, and we read a little from this book, The Old Ways, by Robert MacFarlane, and there was this passage:

The way-marking of old paths is an esoteric lore of its own, involving cairns, grey wethers, sarsens, hoarstones, longstones, milestones, cromlechs and other guide-signs. On boggy ares of Dartmoor, fragments of white china clay were placed to show safe paths at twilight, like Hansel and Gretel's pebble trail. (p. 15, italics...