Thoreau writes in his journal:

Thoreau borrows Grey’s Memoria Technica; New Method of Artificial Memory from Harvard Library (Cameron 1964, 291).

On or near this date, Thoreau wrote to [Thomas] Cholmondeley to tell him that he cannot find the catalog [Thomas] Cholmondeley speaks of, but tells him that he might look at Obadia Rich’s Bibliothecae America Nova published in London (MS letter, NNPM).