Comb teeth and optical telegraph: what they have in common

1. Step 1. Comb teeth — is part of — Comb. A row of teeth.
2. Step 2. Comb — is made of — Bone. Ancient combs were carved from bone and antler.
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.
5. Step 5. Glasses — evolved into — Telescope. The first telescopes were assembled by spectacle makers.
6. Step 6. Telescope — is used in — Optical telegraph. Signals were read through a telescope.

Open Evothings