If "Morse code cannot be use to transmit message reliably over a pipe via tapping", then morse via the tapping of a sounder would also be impossible. The origi

If "Morse code cannot be use to transmit message reliably over a pipe via tapping", then morse via the tapping of a sounder would also be impossible. The original morse sounders used a large relay which went "Click" when operated and another "Click" when released. So a Dit sounds like Click/Click, while a Dah sounds like Click ..... Click. Which is how only one sound (plus spaces) can encode morse. In other words it's all in the rhythm of the sounds.