Igloo interior. 19th century artwork of an Inuit woman caring for a baby in an igloo while food is prepared (right). Built from blocks of ice, the snow and ice insulate the igloo's interior, while a low, long, narrow entrance traps heat while allowing ventilation. This artwork was drawn by the British naval commander Captain George Francis Lyon during William Edward Parry's 2nd Arctic expedition of 1821-1823. This expedition was one of several attempts made at the time to sail the Arctic's North-West Passage, and this artwork is from a journal published in London by Parry in 1824.