What do I have to learn to be able to make astrolabes?

Hi, I'd like to be able to make astrolabes but I was told that I have to be architec and I think this is the most expensive profession. Anyone can tell how much it would cost me to learn how to do astrolabes, more or less. And the septs I have to follow.

From what I remember, you need learn everything - create 1 recipe per all buildings, walls, towers. Around 300 gold