Ordinarily cameras, because of the flatness of their lenses, have a range of only a few degrees, the greatest being scarcely more than ninety.

But this lens was globular, and, like a drop of water, refracted light from all directions.

When placed so that half of it caught the light it "saw" through an angle of 180 degrees, "saw" everything in the room instead of just that little row of bottles on the shelf opposite.
Constance set herself to watch, and it was not long before her suspicions were confirmed, and she was sure that this was nothing more than a "coke" joint.

Still she wondered whether Muller was the real source of the traffic of which Sleighbells was the messenger.

She was determined to find out.
All day she watched through her detectascope.