A Slippery Number: How Many Books Can Fit in the New York Public Library?

In just the past decade, vexingly different figures have been reported — 1.8 million in The New York Times in 2009, four million by The Associated Press in 2013. The library and its current president, Anthony W. Marx, seemed content until two years ago to put the number at about three million, although the figure of 3.5 million had long been used, and appears in the lead paragraph of a Times article from Oct. 1, 1905. (Puzzlingly, the headline says 4.5 million.)

From A Slippery Number: How Many Books Can Fit in the New York Public Library? – The New York Times