Safe!

https://patents.google.com/patent/US171038A/en

How can an umpire be sure a runner has reached first base? In 1875 inventor John O’Neill suggested fitting it with a bell to “indicate clearly and positively, without chance of error, the exact moment when the base is touched by the runner.”

The trouble is that the “enunciating base” will also sound when the first baseman steps on it. Ten years later William Williams suggested an electric bell, which could be heard more clearly by a single umpire behind home plate, but it faced the same objection. Both were forgotten.