Snow's Cholera Data

During the 1854 cholera epidemic in London, John Snow collected data on the location (street addresses) of persons who died of cholera, as well as the location of water pumps in the city. Snow believed (correctly) that cholera was transmitted through contaminated water. Snow's map of London, showing the locations of deaths and water pumps is given below:

Death Data

The table below gives the coordinates of 578 person who died of cholera. The data are a digitized version of Snow's map, with coordinate relative to a set of axes through the center of the map, produced by the National Center for Geographic Information and Analysis. The units are meters. The data have been modified by rounding to the nearest 0.1 meter.

Case	x	y
1	13.6	11.1
2	9.9	12.6
3	14.7	10.2
4	15.2	10
5	13.2	13
6	13.8	8.9
7	13.1	10.6
8	11	11.9
9	15.2	11.7
10	11.1	9.6
11	11.7	13.6
12	12.3	11.5
13	10.6	11.9
14	14.6	10.6
15	16.6	14.3
16	9.5	10.7
17	13.3	10.7
18	15	10.2
19	15.1	10
20	10.9	9.8
21	12.5	12
22	11.8	11.8
23	12.2	10.4
24	13.9	12.8
25	12.3	11.9
26	11	11.9
27	11	9.8
28	13.5	13.3
29	10.8	11.7
30	12.2	13.6
31	13.9	14
32	12.5	11.6
33	15.7	12.7
34	12.9	9.9
35	13	10.2
36	13.7	11.4
37	13.1	11.1
38	13.4	11.1
39	14.8	9.4
40	13.2	13.2
41	9.8	12.5
42	12.5	12
43	13.4	10.2
44	14.4	11.6
45	16	14.2
46	10.9	12
47	12.5	13.4
48	15.8	12.4
49	16.5	14.3
50	11.2	8.6
51	15.8	12.2
52	11	9.8
53	11.7	13.6
54	11.5	12.3
55	11.8	15.1
56	13	13.9
57	14.1	13.1
58	14.8	10
59	12.6	11
60	14.6	12.9
61	12.5	11.2
62	14.5	8.7
63	9.2	10.8
64	17.9	7.2
65	11.2	14.7
66	9.5	10.7
67	10.8	9.9
68	16.1	14.1
69	10.4	10.6
70	13.7	9
71	15.8	13.9
72	12.2	11.8
73	11.5	10.7
74	15.4	11.2
75	15.9	12.2
76	10.2	11.9
77	14	12.8
78	16.5	11.4
79	17.5	11.2
80	13.8	8.9
81	14.1	10.6
82	14.7	11.5
83	12.6	13.4
84	11.7	10.4
85	14.4	12.6
86	15.2	17
87	15.8	13.9
88	13.9	12.7
89	15.2	11.6
90	13.2	12.9
91	12.7	11.3
92	15.1	13.2
93	12.8	11.6
94	13.6	13.2
95	14	13.1
96	15.4	13.3
97	14.8	14.9
98	10.3	11.4
99	10.5	11.6
100	9.9	12.3
101	14.2	9.2
102	13.6	12.5
103	15	9.8
104	15.7	12.4
105	9.2	12
106	16.8	11.4
107	13.3	10.3
108	10.6	11.6
109	8.3	7.2
110	13.4	13
111	14.5	8.7
112	16.8	11.4
113	14.7	11.9
114	10.3	11.4
115	13.2	11.2
116	9.1	13.2
117	15.2	10
118	8.4	7.4
119	15.3	9.8
120	13.3	12.4
121	13.2	9.7
122	12.6	11.5
123	13.9	11
124	13.5	12.5
125	15.2	17
126	11.6	11.1
127	9.4	10.8
128	11.4	9.6
129	11.2	14.8
130	11.9	10.2
131	15	10.2
132	13.6	11.5
133	14.1	13.6
134	10.5	11.2
135	10.3	9.5
136	13.8	12.7
137	13.4	12.4
138	12.6	11
139	15.7	13.9
140	13.8	8.9
141	13.2	12.3
142	15.1	10.1
143	13.2	10.5
144	14.6	11.4
145	14.4	10.3
146	15	14.1
147	13.1	10.6
148	13.4	8.8
149	11.8	9.5
150	16	14.4
151	10.6	10.9
152	14.6	10.6
153	9.3	12.2
154	14.5	11.5
155	10.5	12.3
156	14	12.8
157	10.6	11.6
158	10.6	11.7
159	15.7	6.1
160	11.8	11.2
161	11.8	10.3
162	11.6	11.1
163	15.8	14
164	10.7	11.7
165	13.4	13.3
166	11.2	11.5
167	15.5	12.8
168	14	10.7
169	13.4	12.5
170	14.6	16.2
171	15.3	13.4
172	14.5	8.8
173	11.4	9.9
174	12.5	11.2
175	13.8	11.2
176	10.6	11
177	10.5	11
178	14.8	10.8
179	14.2	12
180	13.3	12
181	10.4	11.8
182	12.5	10.6
183	15	12
184	10.6	9.9
185	13.1	11.1
186	10.1	11.5
187	11.2	11.4
188	12.9	11.7
189	12.2	10
190	12.4	11.3
191	11.9	10.2
192	11.5	11.4
193	11.7	13.6
194	12.5	11.5
195	14.8	12.3
196	14	12.7
197	12.5	13.4
198	9.2	12.3
199	10.4	11.3
200	12.7	9.2
201	9.1	6.3
202	8.3	7.1
203	15.3	13.6
204	11.2	11.4
205	11.8	11.2
206	12.7	11.3
207	11.8	11.2
208	12.2	13.6
209	12.7	11.3
210	13.6	13.4
211	8.8	15.1
212	12.2	11.3
213	16.2	14.3
214	12.8	11.6
215	13.6	13.4
216	12.7	10.2
217	15	11.9
218	13.9	12.7
219	13.6	9.1
220	12.5	13
221	9.9	12.4
222	17.6	7.3
223	11.1	11.1
224	16.7	14.4
225	9.7	11
226	13.4	13
227	13.1	10.6
228	13.7	10.1
229	11.7	11.1
230	13.1	11.8
231	13.1	11.8
232	12.3	11.9
233	14.9	12.8
234	11.5	12.6
235	12.9	11.6
236	11	11.2
237	15.8	14
238	12.9	10.3
239	12.3	11.5
240	9.8	11.8
241	12.7	11.3
242	12.7	12.1
243	16	9.2
244	11	11.9
245	14.1	9.3
246	11	11.7
247	14.5	8.7
248	15.6	11.3
249	9.6	11.8
250	15.5	11.1
251	14.4	12.2
252	11.4	9.9
253	13.7	11.3
254	11.4	11
255	16	9.1
256	9.9	11.9
257	10.8	9.7
258	12.6	11.6
259	9.3	10.7
260	13.8	13.8
261	13.8	13.8
262	14.7	10
263	15.3	10
264	14.1	12.4
265	13.8	10.1
266	11	11.3
267	12.4	10.5
268	14.8	10
269	15	13.6
270	15.4	13.5
271	12.8	14.3
272	11.3	9.8
273	10.5	11.8
274	11	11.2
275	13.4	9.5
276	10.3	11.4
277	9.6	11.8
278	14.5	12.3
279	11.5	11.4
280	12.7	10.7
281	15	12
282	12.3	14.8
283	12.9	10.8
284	15.3	9.1
285	15.8	9.6
286	13.1	13.9
287	12.9	11.7
288	15.3	12.1
289	13	11.8
290	12.5	11.2
291	15.8	13
292	14	13.4
293	13	14.4
294	13.9	14.6
295	10.9	9.7
296	16	14
297	15.1	10.1
298	13.5	12.6
299	11.6	12.3
300	10.7	12
301	16.8	11.6
302	13.9	14.6
303	13.7	11.1
304	13.3	9.6
305	15.7	12.4
306	15.5	11.2
307	11	11.2
308	15.5	11.1
309	11.7	9.6
310	12.4	11.4
311	11.1	11.5
312	9.6	10.9
313	8.3	7.2
314	14	13.3
315	13.2	13
316	15.3	9.3
317	15.5	11.2
318	15.4	7.3
319	16.1	14.3
320	12.4	13.7
321	12.2	11.8
322	15.1	11.7
323	14	12.9
324	9.6	10.9
325	16.3	14.3
326	12.6	10.6
327	10.5	12.9
328	14	12.8
329	15.5	11.3
330	11	11.2
331	13.3	12.9
332	13.9	13.6
333	13.3	9.6
334	12.7	10.7
335	15.4	11.2
336	15.7	13.9
337	13.8	11.1
338	11.7	10.5
339	16.1	14.3
340	12.6	11
341	15.4	11.3
342	16.3	14.4
343	12.5	12.1
344	15.7	12.9
345	11.5	12.6
346	14.2	12.1
347	16.3	10.1
348	13.6	11.2
349	12.6	10.4
350	11.7	11.2
351	8.8	10.9
352	10.9	14.7
353	11.6	11.1
354	13	11.2
355	13.7	11.3
356	11.1	11.8
357	14.6	12.3
358	10.4	11.6
359	13.1	12.3
360	11.9	14.2
361	13.3	10.3
362	9.9	12.2
363	12.7	12.8
364	9.3	10.6
365	11.6	9.5
366	13.1	12.3
367	11.4	11
368	13.6	11.5
369	11.8	13.6
370	16.3	14.4
371	8.7	12.1
372	15.7	12.2
373	12.2	11.4
374	14.8	14.1
375	13.5	8.9
376	15.7	12.9
377	11.9	14.2
378	12.5	12.8
379	14.4	13.1
380	12.2	14.1
381	15.3	11.4
382	11.5	10.8
383	9	11.2
384	10.8	8.8
385	14.9	10.1
386	13.2	11.9
387	13.4	8.8
388	14.4	12
389	12.2	11.4
390	12	14.6
391	13.6	11.6
392	8.8	12
393	13.4	11
394	12.6	12.8
395	15.6	14.2
396	12.5	12
397	12.4	11.3
398	12.4	11.4
399	13.4	12.6
400	12	11.4
401	9.9	11.8
402	12.1	13.6
403	14.4	13.1
404	15.7	12.9
405	13.8	11.1
406	11.4	10.9
407	13.8	14.2
408	15.6	11.3
409	15	10.2
410	14.1	13.1
411	13.2	9.8
412	13.3	13
413	10.9	12
414	12.1	10
415	14	13.9
416	11.3	10.8
417	13.4	13
418	13.5	12.5
419	14.8	12
420	13	11
421	12.4	11.3
422	12.3	14.8
423	13.1	12.4
424	14.8	13.2
425	9.8	12.5
426	14.1	10.6
427	12	14.6
428	16.1	14.2
429	12.7	11.3
430	14.7	10.1
431	8.8	12.1
432	10.5	12.3
433	12.2	14.2
434	11.7	13.6
435	8.3	11.6
436	12.4	13.2
437	16.7	8.4
438	15.7	7.2
439	16.1	14.3
440	14.3	10.5
441	9.7	12.4
442	13.3	12.9
443	16.1	10
444	14.4	10.4
445	13.4	10.9
446	14.5	9
447	14.6	11.4
448	13.7	13.9
449	16.2	14.2
450	16.3	14.4
451	12.8	14.3
452	13.4	11.9
453	11.2	8.6
454	11.6	12.2
455	14.7	11.9
456	9.4	10.8
457	9.5	10.7
458	15.7	11.6
459	14.3	12.5
460	14.2	13.4
461	11.5	10.4
462	15	10.4
463	13.1	12.4
464	11	12
465	11.9	14.2
466	13.5	8.9
467	14.1	13.1
468	10.9	16.5
469	14.2	9.4
470	10.4	11.2
471	15.6	11.3
472	11.3	11.5
473	13	9.6
474	13.6	13.1
475	11.1	11.6
476	14.6	11.4
477	15.2	8.6
478	13.4	10.4
479	16.1	10.9
480	14.3	10.4
481	16.4	14.4
482	12.6	15
483	13.3	10.8
484	11	12.1
485	10.1	10.6
486	15.6	12.6
487	14.2	13.4
488	13.4	12.5
489	10.8	11.6
490	13.2	10.6
491	13.8	12.6
492	11.4	11
493	12.9	9.8
494	13.6	11.1
495	13.3	14.3
496	12.2	11.4
497	14.4	10.3
498	8.9	12.1
499	15.5	14.2
500	14.3	10.4
501	10	11.3
502	13.2	14.3
503	10.5	12.5
504	9.5	10.6
505	10.4	11.2
506	10.9	14.6
507	13.3	11
508	12.6	11
509	13.1	14.2
510	11.6	10.5
511	13.6	10.1
512	13.4	13.1
513	13.7	11.1
514	10.7	12.5
515	12.2	14.1
516	14	13.3
517	14.8	9.2
518	15.1	10.1
519	16.2	9.9
520	15.3	11.4
521	12.5	11.1
522	14.7	11.4
523	12.5	11.1
524	10.9	14.7
525	15.7	12.9
526	11.7	12.6
527	9.5	11.5
528	13.3	14.8
529	13.6	15.3
530	13.4	10.3
531	13.5	12.5
532	11.1	11.1
533	12.9	10.9
534	12.8	16
535	15.3	9.8
536	12.8	11.3
537	9.2	11.1
538	14.4	12
539	15.6	10.9
540	10.4	11.2
541	13	10.7
542	13.2	11.9
543	11	9.7
544	13.5	11
545	9.6	10.6
546	14.5	10.6
547	12.5	11.1
548	10.7	12.5
549	13.3	12.9
550	9.4	11
551	13.4	11.9
552	13.5	11.1
553	13.5	11
554	13.6	9.1
555	14.3	15.6
556	9.6	10.6
557	14.1	15.5
558	12.9	13.8
559	15.4	13.8
560	13.8	12.7
561	11.4	9.9
562	12.4	11.4
563	12.7	11.3
564	13.6	11.5
565	14.1	13.1
566	15.1	10.1
567	15.3	13.6
568	14.7	10.2
569	13.4	12.5
570	12.3	11.9
571	14.3	10.4
572	12.4	11.6
573	12.1	10.3
574	12.4	11.5
575	15.1	10.2
576	17.3	11.6
577	12.4	11.9
578	15	12.5

Pump Data

The table below gives the coordinates of 13 water pumps in London in 1854, relative to the same set of axes as the death coordinates.