Why a Duck?

On Saturday I took a long walk, starting in Hamilton Heights (where there are Canadian pianists around..)  and then walking through what is called Manhattanville.   The main thing I wanted to see was the famous Riverside Drive Viaduct, which spans the valley between 123rd Street and 135th Street.  There is also a wonderful subway viaduct, as the IRT line emerges from underground to cross the valley.   The area is also now a subject of controversy, as Columbia University is expanding and constructing a very large new campus in this area, and has demolished a lot of the old buildings in the area.  The viaduct dates from 1900, and considered a major work of engineering at the time.
Some pictures:

The Columbia construction site has some interesting colors which attracted my eye:

I don't want to know what these yellow tubes are for:

An example of the subway viaduct, nicely painted:

And finally, one of the old buildings which will most likely be torn down:

It was a sunny day and a great walk..


Note:  The title of this post comes from a famous Chico Marx interpretation of the word "viaduct"....