Signal wire e typewriter: o que têm em comum

1. Passo 1. Signal wire — faz parte de — Railway semaphore. A cable from the control post.
2. Passo 2. Railway semaphore — utiliza — Lever. The semaphore is set by a lever.
3. Passo 3. Lever — faz parte de — Typewriter. Each key is a system of levers.

Abrir Evothings