In the absence of special bars or devices for sharpening a knife, it can be sharpened (not to be confused with the concept of sharpening) on a stone. To do this, we select two slightly rough stones and by rubbing them against each other, we create on one relatively flat flat surface.
How to sharpen a knife on a stone?
Then we sharpen the knife, as in the photo, leading it from the handle to the tip of the blade, so that the direction of movement of the knife along the stone is always at one angle, relative to the line of the cutting edge of the blade at the point of contact.
the hook is made of fish or bird bones, then instead of a groove in the center we make a small hole.
The bait is put on the entire hook and part of the fishing line. If a fish swallows such a hook, then it turns around and rises to it across the throat, plunging deep into soft tissue. From such bone and wooden hooks, the fish breaks off quite often, but fishing with them is still possible. When catching small fish, such hooks are practically ineffective.