Chemicals, the eleventh Mechanical <l:6,66>Advance<e>, marks the beginning of mass production and usage of artificial substances. Artificial fertilizers make the <l:2,31>Mechanized Farms<e> possible, while deadly gases make new terrible weapons, used by the <l:1,93>Chem Trooper<e>. New achievements also allow for terraforming <l:5,2>tundra<e>. Unfortunately, widespread usage of chemical agents increases <l:6,91>pollution<e> in your Civilization noticeably.