In 1962 he painted Mount Everest for the National Geographic Society. He eventually painted about 20 maps for the National Geographic including Mont Blanc (September 1965), five maps of the Leeward Islands (October 1966), Sky World of the Himalayas (October 1966), a map of the Pacific Ocean floor (October 1969), The Delta Project in the Netherlands (April 1968), Nepal (November 1971), and A Traveller's Map of the Alps (April 1985).