Fuel and light from animals - Tallow

[Mortblanc]

The Betty lamp was probably the ultimate fat burner.

https://www.google.com/search?q=betty+la...9&dpr=0.95

They could turn any fat laden chunk of crud into a light source.

The simplest I have seen were made from the bowls of large iron spoons with the handle turned into a loop for holding and the tip bent to hold the twisted cloth wick. They were filled with bacon drippings or lard.

Very sooty and inefficient, but still a light source for the poorest in society who could not afford candles or rush lights.

I have seen the cost of candles worked out for equality of cost between then and now and in many cases the simple tallow candle was worth 10 pounds in todays money. That is some expensive light and not to be wasted.