Fishing line and bells?

Robert Watson Watt proposes his idea of how to detect enemies.

29 August 2014

2 minutes

This clip is from

Castles in the Sky

Scottish inventions and discoveries—BBC Scotland
A look at some of the great Scots and their world-famous inventions and discoveries.

Trail: Castles in the Sky
Duration: 00:35
Telephone in a fish tank
Duration: 01:39
"He's building a washing line...in the rain"
Duration: 01:50