It’s Beltane today, May Day, a day traditionally celebrated with bonfires. Here are some smaller flames, but no less fiery.
This is a photo illustrating how, as Wikimedia Commons explains, “different flame types of a Bunsen burner depend on oxygen supply. ”
And also:
Different flame types of Bunsen burner depending on air flow through the valve.
1. air valve closed
2. air valve nearly fully closed
3. air valve semi-opened
4. air valve maximally opened