A cigarette placed in a standard dry ashtray might appear to be out but could continue to smolder, potentially igniting paper or other flammable materials if left unattended.

A moist sponge in the ashtray would ensure that any cigarette placed on it was thoroughly extinguished by contact with the moisture.

The solution is simple and effective.

It reflects safety thinking — the identification of a specific risk in a common situation and the design of an intervention that reduces that risk — rather than the convenience-focused thinking that drives most of Kenner’s other inventions.

The ashtray patent shows that her inventive mind operated across multiple dimensions: convenience, independence, safety, and practical function all appear in her body of work.