Alarm clock and railway track: what they have in common

1. Step 1. Alarm clock — has part — Electric bell. A bell.
2. Step 2. Electric bell — has part — Electromagnet. An electromagnet strikes a small hammer.
3. Step 3. Electromagnet — is part of — Electrical telegraph. Morse’s receiver.
4. Step 4. Electrical telegraph — is used in — Time zones. Synchronizing time by telegraph.
5. Step 5. Time zones — was inspired by — Railway track. Introduced because of railway timetables.

Open Evothings