The Doctor Who Didn't Tell the City

Saturday, 26 September 1908. In a wooden shed below a dam in New Jersey, bleaching powder is stirred into the water that flows to Jersey City, twenty-three miles away. More than two hundred thousand people will drink it. Nobody has told them what it is. The man behind it was a doctor, John Leal. The story is usually told as one man's secret gamble. The records tell it differently: plenty of people knew, a court had left room for it, and the experts who argued against him were partly right. This is what he put in the water, why it worked, and everything else that now happens to water before it reaches a tap: the clumping, the settling, the sand, the chlorine, and three things chlorine cannot do. Sources for every figure, and for every claim about what the record does and does not contain, are pinned in the comments. This film explains how something works. Nothing in it is advice about what to drink. CHAPTERS 0:00 A shed below a dam 1:10 What was in the river 2:10 A contract, a court, a way out 4:20 Kill them in the water 5:16 Inside the shed 6:23 What bleaching powder really does 8:09 One gram in a tonne 9:29 Who knew? 10:27 "I did not." 11:18 What the court judged 12:21 The cheap way out, and two limits 13:18 Inside a modern waterworks 15:43 Three things chlorine cannot do 17:34 Walkerton 18:41 What it achieved 20:03 Both are true THE BORING MACHINE How the machine actually works. #howitworks #water #engineering