Before modern fire starters, flint was a precious resource, and fires needed to be lit without using flint as much as possible. One technique for starting fires was to keep live coals from the previous day's fire.  In order to ensure that these coals were useable, they had to be protected from the elements. As such, live coals were covered at night and reopened the next morning to start a new fire. Precious like an elderly family member, live coals were carefully covered in a thick layer of cow dung or dirt, here compared to fine bedclothes. This technique allowed households to maintain fires without using precious resources.