In early 1951, Everest enthusiast Michael Ward was carefully studying relevant photographs and maps (the Milne-Hink map) in the Royal Geographical Society archives when he happened to find some photographs taken clandestinely by the RAF in 1945. One of these showed the north face of Lhotse and part of the terrain between the head of the Western Cwm and the South Col. Another showed a broad, snow-covered ridge (the Southeast ridge) stretching from the summit down to the South Col, and a clearly separate steeper ridge falling from near the summit down into the Western Cwm.