The book follows the standard 'Then & Now' format with photographs from the nineteenth and early-twentieth centuries on the left with a view from the same spot (or almost) on the right from more recent years. (It amused me to see that the author has sought to copyright the 'Then & Now' format!)
The book starts at the tip of Manhattan and works northward. There are some very interesting historical photographs such as the cast-iron pedestrian bridge over Broadway and the huge Manhattan terminal of the Brooklyn Bridge that looks like a space-ship dropped down into City Hall Park.
Photographs cover the whole length of Manhattan, all the way to the George Washington Bridge. Each is accompanied by a short explanatory text.
A worthwhile book and a good price too. For those who know very little of New York and for those who think they know a lot, all will learn to see the city with new eyes.