Permanent wave and autoclave: what they have in common

1. Step 1. Permanent wave — uses — Heating element. Nessler's first machines heated the wound strands with electric heaters.
2. Step 2. Heating element — is part of — Espresso machine. A heater.
3. Step 3. Espresso machine — works like — Moka pot. A home way to make coffee with steam pressure; the espresso machine (1884) is older than the moka pot.
4. Step 4. Moka pot — has part — Safety valve. A valve.
5. Step 5. Safety valve — is part of — Autoclave. A safety valve releases pressure.

Open Evothings