Principle 2. Taking out

1. Separate an interfering part or property from an object, or single out the only necessary part (or property) of an object.
   Locate a noisy compressor outside the building where compressed air is used.
   Use fiber optics or a light pipe to separate the hot light source from the location where light is needed.
   Use the sound of a barking dog, without the dog, as a burglar alarm.