A good read. Eloquent writing and interesting history. I've just started this one, but am quite gripped by it so far. Here's a sample of the writing (from page 6):
"There (in London) he gained the attention of the prestigious African Society and of its flamboyant secretary, Henry Beaufoy. Impressed with the 'manliness of his person, the breadth of his chest, the openness of his countenance, and the inquietude of his eyes,' Beaufoy propsed that Ledyard probe the length of the Nile, from Cairo to Sennar in the eastern Sudan, a journey never before undertaken by a Westerner."