One can hew wood by standing a log across two other smaller logs, and stabilizing it somehow, by notching the support logs, or using a 'dog' (a long bar of iron with a hook tooth on either end that jams into the logs and prevents movement). The hewer marks a line on the log perhaps with a chalk line or other tool, then chops wedges in the log with a chopping axe down to the line every foot or two. The hewing is done by turning the log on its side and bringing the broadaxe down, chipping off pieces of wood until the wood is down to the marked line. The wedges make chipping easier as long shreds of tree are not removed and so forth, only smaller chips. The result is a relatively flat surface on one side of the log, which can be further cleaned up with an adze, or perhaps a hand plane, or whatever one's imagination can come up with.
This process has been largely obsoleted by the modern sawmill and power tools.
