The cause of London's cholera outbreaks had been identified by John Sutherland (1808–1891) and Dr John Snow (1813–1858; author of the famous map of water pumps near Broad Street). The matter was not decided until Lankester established a committee to look into the latest outbreak. The Committee's report (1854) had sections written by Snow and the Reverend Henry Whitehead, a local curate. They reached the conclusion that the outbreak was attributable to the use of impure water from the well in Broad Street.