visible evidence

Jellyfish blooms are the visible evidence that something is out of balance.

Have you noticed any visible evidence of the oil in the area yet?

The reports came at random from every direction, but there was no visible evidence as to how they were produced.

Men are hurrying about in cabs and on foot with determined-looking faces, but no other visible evidence of the day's tragedy.

Still she stood regarding him without visible evidence of the anger which Lydia thought would have been justified.

In a very few words he welcomed the first visible evidence of relief.

Amidst all this mechanism of outward worship, we regret to say there was small visible evidence of spiritual concern.