Charles E. Key highlights the explorers seeking out the last blanks on the map in The Story of Twentieth-Century Exploration. This is a relatively old volume (1938), cited in Reuben Ellis' Vertical Margins, that covers the exciting happenings within the Modern Age of exploration, including reaching the North and South Poles, searching the Sahara and Gobi deserts, exploring Tibet, climbing Himalayan Peaks, and delving into the interiors of the Amazon, Australia, and New Guinea. Because of the academic nature of Ellis' work, I expected intelligent writing here as well, but I was not quite so lucky. The book is a general-audiences summary of modern exploration, and not a particularly great one. Key focuses on the most sensational or interesting stories on his topics, often introducing them out-of-context---covering, for instance, the Duke of Abruzzi's expedition to the Ruwenzori as though it was the first and only expedition to attempt or climb those mountains. (Remember that Wollaston preceded the Duke and nearly stole his prize.) Key provides little analysis or commentary, though the explorers he omits are often commentary enough, such as "various parties" attempting Kamet before Smythe's crew, or the complete omission of the name Frederick Cook (might have to agree with him there). He includes a couple surprises, such as Freya Stark's travels in South Asia and Hassanein Bey's trip into the Libyan desert.
Regarding Everest, Key has more to say that he probably should. His description of the snows high on Everest is certainly unique, and his setting up of the climbing of Everest as a four-stage gauntlet adds drama, but misses some of the greater difficulties. He covers each of the expeditions up to 1936 (including the 1933 flight over Everest---though he oversimplifies its story), focusing on the actions of climbers high on the mountain. He gives extra room to dramatic moments, such as Smythe's climbing a ice wall while scaling the North Col or Mallory and Irvine's climb into the clouds. His narrative is at least entertaining and mostly accurate. I like that he euphemizes the accomplishments of the 1936 expedition by saying they garnered a good deal of useful information.