Telephone concealed in a fire hydrant.
The device was invented by Schleppenheimer, whom the Chief declares he will murder when he (the Chief) is not only drenched when he answers a call but also splashed by a passing car.
An additional danger is its attraction to collies.
[First seen in Episode #24: "Stakeout on Blue Mist Mountain"; above information from Episode #91: "Diamonds Are a Spy's Best Friend".]