Wetsuit and watt steam engine: what they have in common
- Step 1. Wetsuit — has part — Zip. A zip on the back.
- Step 2. Zip — is part of — Jeans. A zip.
- Step 3. Jeans — uses — Indigo. Indigo.
- Step 4. Indigo — evolved into — Synthetic dye. Synthesizing natural dyes.
- Step 5. Synthetic dye — is made of — Coal. Aniline from coal tar.
- Step 6. Coal — is used in — Watt steam engine. Steam engines were fired with coal.