Oblong quarto; 2pp. subscribers list at the rear, dedication to Prince Albert, lithographed map, 22 tinted lithographed views on ten plates, one folding panorama, all after Allen and drawn on stone by Allen, W.L. Walton, T. Picken, and C. Hague, all printed by Day & Hague, original printed wrappers, preserved in a modern green linen-covered folder, the label on spine. Allen took part in the Niger expedition of Richard Lander and Oldfield in 1832. [but] he is best known as having commanded the Wilberforce in the elaborately equipped but disastrous expedition under Capt. Trotter to the same river in 1841-42. In 1849 he published a "Plan for the immediate Extinction of the Slave Trade, for the Relief of the West India Colonies, and the diffusion of Civilisation and Christianity in Africa by the co-operation of Mammon with Philanthropy." Allen was a Fellow of the Royal Society, and some of his landscape paintings were exhibited at the Royal Academy from 1828-47 (DNB). Coloured plates in order: 1. [Map] A part of the Rivers Niger & Chadda. 2-5. Views of the Nun Branch of the River Niger (4 views). 6. Procession to Ibu 7. Cliffs at Attah. 8. Mountains & Market Canoes near Bokweh. 9. Huts at Joggum. 10. The Palaver. 11. The Confluence of the Rivers Niger and Chadda (panorama). 12. Mount Patteh from Bangadeh. 13. The King giving judgment at the gate of his Palace. 14. The interior of Chief Malem's House. 15. The Morning Call. 16. Attah. 17. Beaufort Island, looking up River. 18. Six miles below the Confluence. Looking up the River. 19. Six miles below the Confluence. Looking down the River. 20. Twenty miles above the Confluence. Looking down / Looking up. 21. The Terry Mountains. 22. The Rennell Mountains. 23. Zagosgi / Looking up the River / Cliffs about 150 feet high / The City of Rabba.