[From the reference in Sotheby Parke-Bernet Catalogue 21, November 1970, lot 220: "two calotypes...in an envelope addressed to H.F. Talbot (postmarked Sept. 10, 1844)." Although the envelope and any letter it originally contained hsve yet to be traced, they might still exist. After passing through more than one hand, the two calotypes illustrated appeared later in Larry J. Schaaf, Sun Pictures Catalogue XV: From Talbot to Turner (New York: Hans P. Kraus, Jr., Inc., 2006), item 21.]