Photo "Incomplete Combustion. Mossmorran ethylene (ethene) plant in Fife. Occasionally waste gases are flared off, often to make an area safe for maintenance work. The gases are mixed with water vapour to make a quieter flame. Usually the burn is clean and there is no visible smoke. For some reason, for a few minutes there was not enough oxygen in the mix of gases and a dense cloud of smoke, unburned carbon, was clearly visible from across the Forth. The fault was soon repaired though and the smoke drifted away." by Richard Webb (Creative Commons Attribution-Share Alike 2.0) / Cropped from original

Flights from Indianapolis to Cockenzie