Qoraal sii wata faqradan--dhakhtarka ingiriiska John Snow waxa uu isticmaalay jaantuska Voronoi-ka sanadkii 1854 si uu u muujiyo sida dadka ugu badan ee ku dhintay cudurka jadeecada ee Broad Street
wuxuu ku noolaa meel u dhaw Bamka Broad Street ee cudurka qaba ka badan Bam kasta oo kale.