Procedure and device to determine the depth of the seas.
FR561539A
Method for determining the direction of acoustic waves
FR561538A
Materials testing process
ES84187A2
An acoustic receiver.
FR558623A
Receiving arrangement on ships for determining the direction of sound sources
ES81196A1
Procedure and device to determine the depth of the seas.
ES80597A1
Underwater acoustic receiver device.
ES80296A1
An acoustic receiver.
ES78359A1
An acoustic reception facility on board ships.
ES76046A3
Underwater sounder.
ES74742A1
A device for receiving acoustic signals without disturbance.
ES74647A1
A sound transmitter actuated by a striker device.
ES74641A1
Improvements in acoustic devices for underwater acoustic signals.
ES74648A1
A purely elastic coupling acoustic device.
ES74585A1
Improvements in electromagnetic devices, especially underwater acoustic devices, with their corresponding construction method.
ES74520A1
Arrangement to prevent buzzing in the telephone as a consequence of the circuitry of various transmitters transformatively linked to the telephone, for example acoustic signal devices.
ES74519A1
Provisions applicable to acoustic devices that work under water.
ES74517A1
Device for the appreciation of the increases determined by oscillations and by multiple tuning in underwater acoustic transmitters and receivers.
ES74516A1
Improved radiation system for underwater acoustic devices.
ES74521A1
Transmitter arrangement for underwater acoustic signals.
