Show SOUND TO CONTROL MACHINE Remarkable Invention Demonstrated in London Londo Is Based Upon the Principle of Resonance i iI I The distant control of mechanical I operations by sound as demonstrated In London depends upon the principle of resonance or the setting up of ref reg re- re f g sympathetic vibrations by sending out the note for which the apparatus ap ap- ap- ap Is tuned The resonator consists of a telephone telephone telephone tele tele- phone transmitter and receiver placed near together face to face In a closed cylindrical casing with a tube containing containing containing contain contain- ing a u piston extending at the back of the r receiver The piston lengthens or shortens the column of air all behind the receiver and thus changes the vibration vibration vibration tion note of the transmitter and and r receiver re re- celver diaphragms The transmitter Is connected to the primary current of an ain n Induction coil coll with switch battery resistance and an ordinary post office rela relay In circuit the receiver Is coupled coupled coupled cou cou- pled to the Ule secondary circuit When the proper note vibrates the diaphragms diaphragms diaphragms di di- the armature of the tile relay is moved closing the local circuit and this can be adapted for tor starting and stopping an engine releasing bombs or other purposes For controlling a dirigible the sounds might be sent from the ground b by a siren the note of which would be adjusted by byar ar varying the speed Different Different Dif DU ferent notes could be made to perform different requirements and in guiding an airship turning the rudder to the to the left elevating depressing speeding up the engine and slowing It down would each have bave Its special note To avoid discovery of the means of at performing any operation the apparatus apparatus a atus tUB could be designed to respond after after attel af at af- af ter tel a definite number of repetitions of the right note or only after a combination combination combi combi- nation of different notes |