Technical Questions regarding the Dream Sequence

Just wondering if any of you on the board are familiar with the production details of the dream sequence.

1.) I'm looking for what effect Murnau uses inside the hotel to create the blurry super-imposed like images?

2.) What Murnau used to create the scene transition between the exterior and the interior hotel? I think it may have been water poured over the camera lens to create the obscurity but I can't be for certain.

Any help would be greatly appreciated.