Manufaktura is located just east of Plac Jana Natalisa, in the Handlowa of Wyzima. It is the newest weapons factory in all of Temeria apparently and produces more weapons than all the swordsmiths combined. However, their motto seems to be "cheap, fast and plenty", rather than workmanship. They produce swords, hatchets, armor and arrowheads, for the arbalesters of course, can't forget them!
When Geralt first enters the shop, he sees a number of tradesmen busily forging broni, overseen by their foreman. There is also an alchemist, toiling away at his bench in the back. Being the curious type, the witcher strikes up a conversation with the foreman which proves quite interesting. For instance, he learns that there are competing factions within the royal entourage and that at least one faction is stockpiling weapons. Hmmm...
The alchemist is also interesting to talk to, if a bit abrupt in his manner. He's a snob about alchemia, which he considers superstitious rubbish and its practitioners, notably Kalkstein, quacks. He thinks of himself as a scholar, not an alchemik. He asserts that science alone will survive the test of time while magic and alchemy will disappear.
Our witcher is never one to let others run down his friends, so he defends his favourite alchemist and in the process manages to convince the "scientist" of the validity of Kalkstein's theories and get a couple of handy books out of the deal: Samum and Sekrety mistrzów Południa. He can also trade a piece of czerwona meteoryt for a copy of Zerrikańska alchemia.