The New York Public Library is not only arguably the most prominent Beaux Arts building in the city, it’s arguably the best. Only the Metropolitan Museum comes close. The old Penn Station was spectacular, but had some failings as a functional design, while the NYPL, amazingly, has its public rooms functioning almost the same now (barring epidemic shut-downs) as they did in 1910. The picture above, taken shortly after completion, gives a sense of the exterior. The grand entrance on the left faces Fifth Avenue, while 42nd Street on the right gets a still-imposing but clearly secondary facade. So far so good, as far as the principles of Beaux Arts design go; it goes without saying that the interior matches the exterior in grandeur.
Here’s the back of the building, facing Bryant Park and ultimately Sixth Avenue (and the tall building on the far right was the Engineers Club when this photo was taken, long since converted to apartments):
The big arched windows are the main reading room. The facade below that…no, they did not run out of money to finish it. The reading room sits on top of the original stacks (since supplemented with more stacks under the park and a long-term storage facility off-site) so that the books can be delivered to readers via dumbwaiter. Here’s a view of the stacks immediately after construction, before the books were delivered:
There are sockets for light bulbs in the ceiling, but that’s a dark space. The vertical strip windows on the west facade align with the aisles, to get whatever daylight is available inside.
Contrast helps when discussing history and theory of any kind, including architectural history and theory. It’s easier to explain the rise of modernism if you focus on the heavy ornamentation and rigid rules of the classical styles popular in the US in the late 1890s and early 1900s. But if that rear facade, with the fancy arched windows for people and plain strip windows to illuminate the book stacks, doesn’t represent simple functionalism, if it doesn’t embody the idea that form follows function, I don’t know what does.