Ethel B. Clark began work at Dumbarton Oaks after the institution transitioned to Harvard in 1940. She was hired to care for the rare book collection and oversee the small bindery operation meant to publish on-campus the works of Dumbarton Oaks scholars. During her tenure at the bindery, which lasted until 1942, they bound 388 volumes. Otto Zahn took over in 1942, allowing Clark to focus on her duties as curator of rare books. At the time, Mildred Bliss was avidly seeking to expand the collection with the help of Beatrix Farrand. A number of book lists from the 1940s record the acquisitions that fell under Ethel Clark's care.
During the war years, Clark returned temporarily to bookbinding. In 1943-44, she supervised a volunteer group that took equipment and supplies to Walter Reed Hospital where they taught convalescing soldiers the art of bookbinding. During this time Clark also gave a number of informal talks to Dumbarton Oaks staff, scholars, and fellows on the topics of rare books. In 1944, she reached retirement age, and at this time her salary was reduced and her title was changed to Honorary Keeper of Rare Books. Clark lived in the Acorn Cottage for free for a time, and continued supervising volunteers. Even after she stopped working regularly at Dumbarton Oaks in 1948, she retained Emerita status until 1965.
References:
Dumbarton Oaks House Archives.
Garden Archives Correspondence.