The Pump on Broad Street 7 September 1854

You are a member of the Board of Guardians of St James’s parish, London.

A sudden cholera outbreak has killed hundreds of people in Soho within days. A local physician, Dr John Snow, asks the board to remove the handle from the public water pump on Broad Street, arguing that its water is spreading the disease.

Known information

The outbreak began at the very end of August and is concentrated in the streets around Broad Street.
Most doctors believe cholera spreads through ‘miasma’: bad air from filth and decay.
Snow has found that many of the dead lived near the Broad Street pump or drank its water.
The pump’s water looks clear, and many local people prefer it to other supplies.
Deaths may already be falling, partly because many residents have fled the area.

Reveal what happened (spoilers: decide first)

Fact

What actually happened

The board agreed to remove the pump handle. (Remove the pump handle)

Snow presented his evidence to the Board of Guardians on the evening of 7 September 1854, and the pump handle was removed the next day. By then the outbreak was already declining; in total it killed around 600 people. Removing the handle may have prevented further cases, but Snow’s theory that cholera was spread by contaminated water was not widely accepted during his lifetime.

Important

Possible consequences · Analysis and speculation, not fact

Leaving the pump in use might have allowed a second wave of infections as families returned. Because the outbreak was already falling, historians debate how many deaths the removal actually prevented.

History does not reveal what would definitely have happened under the other choice. Many factors could have changed the outcome.

Context · Why it was decided this way

The local curate, Reverend Henry Whitehead, at first doubted Snow but later investigated the outbreak himself and identified a probable source: a baby’s soiled nappies washed into a cesspool close to the well.

Snow’s map of deaths around the pump became one of the most famous images in public health. The bacterium that causes cholera was identified by Filippo Pacini in 1854 and later by Robert Koch in the 1880s, whose work brought wider acceptance of germ theory.