I've only found this in ToT cities.bmps
How can one active it?
I've searched scenario making guides over the net but they only mention the renaissance people gfx(Invention and Philosophy IIRC).

Thanks in advance.

Mongols redux certainly uses it.

Invention. William Keenan omitted it from the last version of his Test of Time Advance Slot Properties article (http://sleague.civfanatics.com/COC/guides/tot_advances.shtml). I added it to the Scenario League version (http://sleague.civfanatics.com/index.php/Test_of_Time_Advance_Slot_Properties).

Thanks man.