I really enjoy the character development in this manga, but dear god every time the author introduces some item that supposedly no one knows about it makes me shake my head. Sugar beets were the primary source of sugar before Europe started conquering Africa, screw pumps and air pumps for wells and rivers existed in 200 BC and compasses have been reported to be used as early as 850 AD. Assuming this world is approximately 1300 AD in terms of development, AND ALSO HAS MAGIC, it should be expected that these trivial items would have been long since discovered and likely improved upon. /rant