Typical Experimental City may look like this. At left is computerized communications complex; at center lies atomic power plant, while at right is greenhouse for vegetables and greenery.
The up-to-date scientist has little difficulty in predicting certain things that will happen in ten or fifty years, but a hundred centuries hence is a larger order, even for the most intrepid imagination. That practically nothing of our present civilization will be left after 10,000 years may be safely predicted. We may also prophesy that human beings, a hundred centuries hence, will live in entirely altered circumstances from those in which we now exist.
Our illustration depicts one of the future cities floating high in the air, several miles above the earth. The question of sustaining such a large body in a rareified atmosphere will prove to be of little difficulty to our future electrical engineers. Just as we construct leviathans of the sea to-day, some of them weighing as much as 50,000 tons we shall construct entire cities weighing billions of tons, which will be held in space not by gas balloons, propellers, or the like antiquated machinery, but by means of gravity-annulling devices. Already experiments have been made whereby it has become possible to reduce the weight of substances by electrical forces.
Tomorrow's map will be vastly different from today's. Great patches over much of it will indicate the super-metropolis cities which are already evolving out of our once-separated urban centers.
The "regional cities" of tomorrow will be nearly continuous complexes of homes, business centers, factories, shops and service places. Some will be strip or rim cities; some will be star-shaped or finger-shaped; others will be in concentric arcs or parallels; still others will be "satellite towns" around a nucleus core. They will be saved from traffic self-suffocation by high-speed transportation - perhaps monorails that provide luxurious nonstop service between the inner centers of the supercities, as well as links between the super-metropolises themselves.
Robots tend crops that grow on floating platforms around a sea city of the future. Water from the ocean would evaporate, rise to the base of the platforms (leaving the salt behind), and feed the crops.
As city life grows more complex and crowded, the need for large-scale control of environment and equipment will demand robotic hands at the helms of trains and boats and planes everywhere.
The first center to be seen is that structure, or complex of structures, in which the control of the business activities of the cities is housed. Here is located the seat of government of the city's practical affairs, including its three chief branches - legislative, judiciary and executive. 
Rather than a floating city, today we have an image of undersea cities from the book Out of Time: Designs for the Twentieth-Century Future.
"Imagineers said that when they were planning Tomorrowland, Walt would carry around books on city planning and mutter about traffic, noise, and neon signs, and he kept three volumes in his office to which he frequently referred: Garden Cities of Tomorrow by Sir Ebenezer Howard (originally published in 1902 and reissued in 1965), which promoted a vision of a more pastoral urban life; and The Heart of Our Cities and Out of a Fair, a City, both by an architect and mall designer name Victor Gruen, who urged the reconceptualization of the city as more ordered, rational and humane."
As promised, here is page 12 of the amazing 1979 book Future Cities: Homes and Living into the 21st Century. 
