Unimpressed with Pressure
The surging oil finally drops in pressure enough for you to get up to the signal fire. There's a steady burble of crude oil underneath the pyre, and flammable fumes shimmer above it. You bang a couple of rocks together until you get the attention of a passing interstellar starship, which lights the pyre for you with its photon beam. Success!
Occurs at the Oil Peak.
- In chapter 12 of The Hitchhiker's Guide to the Galaxy, a broadcaster states "and we'll be saying a big hello to all intelligent life forms everywhere ... and to everyone else out there, the secret is to bang the rocks together, guys."