Argon discharge globe

Argon discharge globes were devices owned by the Doctor and stored aboard his TARDIS. While visiting the human colony on the planet Frontios, the Fifth Doctor asked Tegan Jovanka and Vislor Turlough to fetch the globes to have some lights for the colony. However, Tegan and Turlough were unable to access it, as the TARDIS doors leading from the console room to the inner corridors would not open. (TV: Frontios)

Bernice Summerfield found an argon discharge globe in the tomb of Saint Celestion on Agora. (AUDIO: Bad Habits)