Each vessel, one at a time, is turned upside down over charcoal, and pieces of pine bark are built up all around and over it like a square little hut, then ignited.

Care is taken that no piece of bark comes so near to the jar as to touch and injure it.

Where bark cannot be readily procured, wood is used.

The heat first turns the clay dark, and afterward a pretty yellow colour.
There is one industry which has a peculiar bearing on the whole life of the Tarahumare, namely, the making of native beer.
Nothing is so close to the heart of the Tarahumare as this liquor, called in Mexican Spanish _tesvino_.

It looks like milky water, and has quite an agreeable taste, reminding one of kumyss.