From the Stowe 1848 Catalogue:

The Ante-Library or Print Room, is entered from the Library. This apartment formerly contained a most extensive collection of engravings and ethchings of all schools and masters. The whole collection, except the English School of Engravers and the English Historical Portraits, formed a sale of thirty days’ duration, in the months of May, June and July, 1834 at Phillip’s Rooms in New Bond Street. The total Prints amounted to upwards of 55,000 and the sum realised was little more than £6700. The remainder of the collection will be sold with the Library at Sotheby’s.