• The earliest of our photos of the Mer de Glace glacier was taken in 1919 (21 September, p 8).
• The United Nations definition of “extreme poverty” is an income of US$1.90 per person per day adjusted to 2011 purchasing power parity (7 September, p 46).
• Flaming hell. Harold Gasson was employed by the Great Western Railway to stoke fires, not extinguish them (Feedback, 14 September).
