On Divers Arts

Here's a book that would be an interesting read for artist and craftspeople, especially those who work in glass or metal:
"On Divers Arts" is a book by a medieval monk and artist named Theophilus. It describes the technical processes used for painting, working in glass, and metalworking. I might be a bit nerdy, but to me it is fascinating to read about how things were done so long ago, when everything needed to be made from scratch, and there were no such things as electric kilns, power tools, or even torches. Most of it seems like pretty credible technical information, but there are a few questionable parts. Take, for instance, this passage from a chapter on hardening tools:
"Take a three year old goat and tie it up indoors for three days without food, on the fourth day give it fern to eat and nothing else. When it has eaten this for two days, on the following night shut it up in a very large jar perforated at the bottom, and under the holes put another vessel, intact, in which you can collect its urine. When enough of this has been collected in this way during two or three nights, let the goat out and harden your tools in this urine.
Tools are also made harder by hardening them in the urine of a small red-headed boy than by doing so in plain water."
Hmmm...
First of all, this was clearly written long before people were concerned with animal rights. Second, where would you get a jar big enough to fit a goat inside?
It would probably be easier to get the small red-headed boy pee instead, but people might wonder what you were up to. On second thought, they would probably be just as curious about the goat in a jar.
Maybe you should just harden your tools in water and deal with them not being as hard as they could be.