A couple of years ago Salvatore Magaddino, who oversees the distribution of materials for the New York Public Library, complained at a meeting that he was having trouble recruiting book sorters, the people responsible for sorting the millions of books sent each year from one branch library to another.

“It was a mundane, boring job,” Mr. Magaddino said the other day, standing next to a result of that complaint, a gigantic new automated book sorter housed in a renovated warehouse in Long Island City, Queens. This machine  believed to be the largest of its kind  has eliminated much of the drudgery since it was turned on two months ago. Now, when a library visitor anywhere in the system requests a book located at another branch, the automated sorter does the work of routing it.

Here is how it works: On one side of the machine, which is two-thirds the length of a football field and encircled by a conveyor belt, staff members place each book face-down on a separate panel of the belt. The book passes under a laser scanner, which reads the bar code on the back cover, and the sorter communicates with the library’s central computer system to determine where the book should be headed. Then, as the conveyor belt moves along, it drops the book into one of 132 bins, each associated with a branch library. It’s sort of like a baggage carousel that knows which bag is yours and deposits it at your feet.

Image Books arriving to be sorted at the Long Island City facility. Credit... Uli Seit for The New York Times

When he spoke up at the meeting, Mr. Magaddino did not even know that such machines existed. But soon after, a librarian who had been there pointed him to a YouTube video of an automated sorter in Washington State. Mr. Magaddino did some lobbying, and the library decided to order one.