Masters of Space - Morse, Thompson, Bell, Marconi, Carty
Up to the middle of the seventeenth century the possibilities of the naval signal systems were limited indeed. Only a few prearranged orders and messages could be conveyed. Unlimited communication at a distance was still impossible, and there were no means of sending a message to meet an unforeseen emergency. So cumbersome were the signal systems in use that even though they would convey the intelligence desired, the speaking-trumpet or a courier was employed wherever possible.
To the officers of the British navy of the seventeenth century belongs