Ground, water, and air conduction Several wireless electrical signaling schemes based on the (sometimes erroneous) idea that electric currents could be conducted long-range through water, ground, and air were investigated for telegraphy before practical radio systems became available.
Ground, water and air conduction Several wireless electrical signaling schemes based on the (sometimes erroneous) idea that electric currents could be conducted long-range through water, ground, and air were investigated for telegraphy before practical radio systems became available.