Gunpowder, printing press, fully-rigged ships, hot air balloons, black-powder musket, cannon, sailing warship
Renaissance/Colonial (TL 4)
Cars, airplanes, radio, ocean liners, submarines, battleships, tanks, machine-guns, fighter aircraft, fission bomb, flak jacket, hydroelectric power, alternating current electricity, major surgery, antibiotics
Coexisting with: World War I / II (TL 6)