The "Arcade Railway," if constructed, contemplates the use of the width of the streets and avenues under which it passes, excepting five feet on each side, to secure the foundations of the buildings. The road will contain sidewalks, roadway, lamp posts, telegraph wires, hydrants, and sewers the whole covered with arches of solid masonry, rendered water-tight, and supported by heavy iron columns. The routes selected are the line of Broadway from the Battery to the intersection of Ninth avenue, thence to Hudson river; also branching at Union square, and following the line of Fourth avenue to the Harlem river. It is estimated to cost over $2,000,000.

The "Viaduct Railway" is another style of elevated road. This wealthy company proposes to erect its lower depot at Tryon Row, causing its road to form an easy connection with the East river bridge. This road, if constructed, will run through the rear of the blocks, have a line on the eastern and one on the western side of the city, each extending to Westchester County. It is to be built on brick arches supported by heavy iron columns, which will themselves stand on inverted arches of solid masonry constructed in the ground. It is estimated to cost from $10,000,000, to $20,000,000. One of these roads is certain to be constructed at no distant day.

Nassau, a narrow and gloomy street, has long been the trade centre of cheap and miscellaneous books, though much of this has lately found its way up town.