I calculated 100 because 1/10 of 100 is 10, which is what ND does: 10 happiness. I wanted to show that FP is often better than ND - not just on huge maps.
good argument
Chichen Itza (20)
Eiffel Tower (16)
Machu Picchu (15)
Notre Dame (19)
Sistine Chapel (11)
Statue of Liberty (14)
Sydney Opera House (11)
Forbidden Palace (10)
Great Library (21)
Great Wall (0)
Hagia Sophia (27)
Hanging Gardens (21)
Oracle (14)
Porcelain Tower (15)
FP, is great if you have happiness-issues. Imho in many cases the best happiness wonder. Maybe the effect isn't shown and noticed. ND - bang , 10 Happiness, but FP at begin maybe 5-7 and the gain grows with the size and time.
Great Wall : Civ isn't a tower defense. Maybe it can imagine a picture of safety, but the backbone of safety in civ are units.
@Kaiser and SoL
There are rather often cities, where no mines or lumber mills are avaible. but maybe this cities have some specialist slots, so they can get some production.
SoL becomes really awesome, if you have also have the liberty SP for 50% less unhappiness and 50% less food consume for your specialists.
A specialist cost then only 1 food and 0,5 unhappiness* and with SoL +1 production. Unless you still have free specialist slots, you transform 1 food into 1 production. It doesn't matter ( until, max. specialists*) if you have farm or mines. AND a specialist still produce something else, like culture,rp,gold,hammers and give you great person points. Further it makes base rp through population more effective vs. unhappiness. If you have connected the city you also get 1g trade for only 0,5 unhappiness per specialist. The only disadvantage is, that specialists still count in the same way for the needed food for city growth.
--> The total return of a specialists with SoL and Liberty SP is excellent. ( Imho, hardly any have finished mercantilism sp also, then a specialist can into space

)
Also togehter with many maritime cities it doesn't matter, at which terrain you build a city. You don't need land for your cities anymore - to have a productive city.
edit : also note, that an unemployed get one hammer. With SoL and Liberty 2 hammers for 1 food. You may only want farms ...
Is SoL without liberty good ... still depends on how much specialists you have.
Is Liberty without SoL good ... hardly that good, se wouldn't be that productive. In a very developed se , SoL brings you 33-50% of all hammers ?
SoL scales with size of empire(specialists) and number of maritime cities to be a must have on huge maps ( together with liberty and maybe also mercantilism* ) ?