[DF4:Sages] Weight of Spellbooks

[wmervine4]

In chapter 4, pages 13-14, the rules are described for pricing out books as spellbooks. The table at the top of page 14 specifically shows that an Average spellbook with 3 spells weighs 12 lbs., but the line beneath this for +1 also shows 12 lbs. Does this mean that additional spells beyond 3 do not increase the weight of a spellbook, or that each additional spell increases the weight by an additional 12 lbs. per spell?

If it's 12 lbs. for 3+ spells, it seems a little funny that I could put 30 spells into a spellbook and it still only weighs 12 lbs. On the other hand, if it is 12 additional pounds per spell, a spellbook with 4 spells would weigh 24 lbs, 5 spells would be 36 lbs., and so forth, which seems excessive since the difference between 2 and 3 spells is only 6 lbs. (6 lbs. for 2 spells, 12 lbs. for 3).

I'm just wondering which is the correct way to handle this. The way its written in the table (no "+" before the 12 lbs.) makes me think that only the cost increases for additional spells, not the weight.

This makes me wonder though, especially if the weigh maxes out at 12 lbs., what is the practical upper limit of spells in one book, if any?