Night and day are all one, for the magnetic light increases automatically as the day-light wanes; and the business parts of the city swarm as much at midnight as at high noon. In the old times, I am told, part of the streets was reserved for foot-paths for men and women, while the middle was given up to horses and wheeled vehicles; and one could not pass from side to side without danger of being trampled to death by the horses. But as the city grew it was found that the pavements would not hold the mighty, surging multitudes; they were crowded into the streets, and many accidents occurred. The authorities were at length compelled to exclude all horses from the streets, in the business parts of the city, and raise the central parts to a level with the sidewalks, and give them up to the exclusive use of the pedestrians, erecting stone pillars here and there to divide the multitude moving in one direction from those flowing in another. These streets are covered with roofs of glass, which exclude the rain and snow, but not the air. And then the wonder and glory of the shops! They surpass all description. Below all the business streets are subterranean streets, where vast trains are drawn, by smokeless and noiseless electric motors, some carrying passengers, others freight. At every street corner there are electric elevators, by which passengers can ascend or descend to the trains. And high above the house-tops, built on steel pillars, there are other railroads, not like the unsightly elevated trains we saw pictures of in our school books, but crossing diagonally over the city, at a great height, so as to best economize time and distance. The whole territory between Broadway and the Bowery and Broome Street and Houston Street is occupied by the depot grounds of the great inter-continental air-lines; and it is an astonishing sight to see the ships ascending and descending, like monstrous birds, black with swarming masses of passengers, to or from England, Europe, South America, the Pacific Coast, Australia, China, India and Japan.