Postcards from 1900 depict tech of 2000

This collection of German postcards were originally give-aways in Hildebrands chocolates in 1900 — they depict the world as it would be in 2000. Included are a water-unicycle, slidewalks, locomotives pulling houses, personal airplanes, weather control systems, amphibious railways, police X-rays for seeing through walls, and, of course, zeppelins. Beautiful artwork, too.