A reader points me to the precedent of the Ixtoc oil spill in the Gulf of Mexico in 1979. The rate of discharge was 10 – 30,000 barrels a day, compared with 12 – 19,000 now estimated for the BP spill. And the oil kept gushing for ten months before it was plugged. 3 million barrels of oil hit the coastline. It could be worse.