Wooden shaft and glasses: what they have in common

1. Step 1. Wooden shaft — is part of — Harpoon. A stick for throwing or striking.
2. Step 2. Harpoon — is made of — Bone. The oldest harpoons (Katanda, ~90,000 years ago) are carved from bone.
3. Step 3. Bone — is material for — Spectacle frame. The first frames were made of bone and horn.
4. Step 4. Spectacle frame — is part of — Glasses. A frame.

Open Evothings