[London, Royal Geographical Society], 1848.
Octavo, pages 26-37 (Gregory), and pages 38-45 (Helpman), plus a folding map ('Part of Western Australia to illustrate the Journals') and pages 74-76 (three pages of information 'inserted for the purpose of correcting some inaccuracies in the Papers by the Messrs. Gregory and Lieut. Helpman').
Disbound, and now protected between flush-cut card and sheets of Mylar held together with a plastic slide binding bar; in excellent condition.
Extracted from the 'Journal of the Royal Geographical Society', Volume 18, 1848. McLaren 9356 (Gregory) and 9765 (Helpman), but not noting the folding map or the corrigenda.