ALLEN, William (1793-1864) & T. R. H. Thomson. A Narrative of the Expedition ... to the River Niger, in 1841. Under the Command of Captain H.D. Trotter. London: Richard Bentley, 1848. 2 volumes, 8°. Engraved portrait, 2 folding maps and 15 plates (one caption cropped, 2 shaved). Later 19th-century green polished calf, gilt spines with red morocco lettering and numbering pieces, double gilt fillet round sides, marbled edges. Provenance: H. E. Butler, 1863 (presentation inscription on an endpaper from Montagu Curzon on the former's leaving Eton). FIRST EDITION. (2)