That would be none other than the New York Public Library for the Performing Arts. “It regularly films dance productions in the city, preserving the present for the future; it aims to have a copy of every dance book ever published; it possesses treasures going back centuries. And its doors are open to the public as well as to specialist researchers.” Alastair Macaulay looks at a few of its gems, from a 1453 treatise to 1933 films of Balinese dance. — The New York Times