“The deaths which occurred during the fatal outbreak of Cholera are indi- cated in the accompanying map, as far as I could ascertain them,” a version of the map published in On the Mode of Communication of Cholera (January

inner dotted [stippled] line. 1855; 1855-01 in Supplementary Figures), modified by the addition of an John Snow, “Dr. Snow’s Report,” in Cholera Inquiry Committee, Report on the Cholera Outbreak in the Parish of St. James, Westminster, during the autumn of 1854 (presented to the committee on 12 December 1854, pub- lished with the entire Report in August 1855), 107.

Digital repair of tear in original by David Beem. The tear is evident in Figure 12.6 of the Snow biography (http://johnsnow. ) where a solid line is used instead of dots to enhance legibility. matrix.msu.edu/images/online_companion/chapter_images/fig12-6.jpg “The outerdotted line on the map surrounds the sub-districts of Golden Square and Ber- wick Street, St. James’s together with the adjoining portion of the sub-district of St. Anne’s, Soho, extending from Wardour Street to Dean Street, and a small part of the sub-district of St. James’s Square, enclosed by Marylebone Street, Tichborne Street, Great Windmill Street, and Brewer Street (108). . . . The pump in Broad Street is indicated on the map, as well as all the surrounding pumps to which the public had access at the time of the outbreak of Cholera. . . . The water of the pump in Marlborough Street, at the end of Carnaby Street, was so impure that many persons avoided using it; and I found that the persons who died near this pump, in the beginning of September, had water from the Broad Street pump. The inner dotted [stippled] line on the map shews the various points which have been found by careful measurement to be at an equal distance by the nearest road from the pump in Broad Street and the sur- rounding pumps; and, if allowance be made for the circumstance just mentioned respect- ing the pump in Marlborough Street, it will be observed that the deaths either very much diminish, or cease altogether, at every point where it becomes decidedly nearer to send to another pump than to the one in Broad Street. At these points I ascertained that the people did generally send to the pump which was nearer” (109).