A Gulf of Alaska Low, a central US High, and a dry flow in between will all conspire to give us sunny and warm weather for the next several days. The first few days of fall (it starts 1:21 am local time Wednesday) will hang on to summer conditions. Highs will be in the upper 80s into the weekend, the mid-80s over the weekend, and will fall to the 70s the first of next week.

Boiling oil fire

Continuing the discussion of boiling oil: Of course, you’ve all seen the movies. The invading armies, most wearing full suits of armor, make a valiant (or dastardly, depending on whose side you’re on) charge to scale the castle walls, only to turn into Spam in a Can as the castle inhabitants pour a swimming pool’s worth of burning oil down upon them. But Hollywood stereotypes aside, I found apparently it is unlikely they used any oil at all to pour on the marauding hoards.

Boiling Oil.

For one thing, oil was a pretty precious commodity back then, and it wouldn’t be wasted when there were better alternatives. Most of the oil available was derived from animal fats, with small amounts of vegetable oils. They never would have had enough to mount an extensive defense, especially when you consider castle sieges could last for months.

'Dang Italians, tricked us again!'

But the castles do have platforms with holes in their floors (called “Murder Holes”) that seem perfect for pouring some kind of liquid through. In all likelihood, plain old boiling water was used… in particular, waste water. Whether it was waste water from the kitchen or from the latrines was beyond the scope of my research, and quite frankly, I’d rather not dwell on it too much.

Water wasn’t the only weapon available through the Murder Holes. They were also very handy places in which to launch missiles of various kinds down on attacking forces, such as large rocks or other castle detritus. I have seen it proposed that heated sand may also have been used, which can get a lot hotter than any fluid can. Lead is also a possibility, since most castles kept a supply of it for repairing roofs. But if you want a candidate that would give you that nice flaming effect, the most likely substance was pitch. Pitch was used to caulk and to preserve things like rope, and it liquefies AND catches fire when heated. It seems pitch might have been the medieval napalm of choice.