Jón Árnason was librarian at the Diocesan Library, which was later called the National Library from 1848 to 1887. He was the first employee of the library, but before that the library's board of directors had been working on a part-time basis. The library was formally established in 1818 and opened for use in 1825. It was housed in the Cathedral Loft until 1881 when it moved to the Althingi House.

Jón received book donations to the library, including from abroad, while many institutions and individuals sent publications to the library, especially on the occasion of the 1000th anniversary of the settlement of Iceland in 1874. Book cataloging was the most extensive part of the work, and Jón left numerous records in the library's archives and two printed records; one record in manuscript from 1849 and a record of books donated to the library in 1874.

The catalogue is the highlight of September, marking 150 years since these book donations in connection with the 1874 National Day.

The list of books donated to the Stiptis Library in 1874 is available here.