Hm, okay, to remove the difference in size, we remove the proportion out of the equation... 1200*(6*7)/(6*6)=1400. A Space Needle of the size of the Colosseum would have a bonus of 1400 happiness. Riiight... I am still waiting for an announcement, the Needle be a very late April fool's hoax. Or at least the bonuses respective their values.