Letter box
device · 1653 · Early modern era
A box for letters.
What it is made of
- Mailbox body — has part. A steel box.
- Letter slot — has part. A slot protected from rain.
- Lock and key — has part. A lockable door for collection.
Principles and materials it uses
- Postal service — uses. The post.
- Wood — is made of. The first letter boxes were wooden.
- Cast iron — is made of. Later — cast iron.