Reprise: Shut down the pump

British doctor John Snow couldn’t convince other doctors and scientists that cholera, a deadly disease, was spread when people drank contaminated water until a mother washed her baby’s diaper in a town well in 1854 and touched off an epidemic that killed 616 people.
[...]
Dr. Snow believed sewage dumped into the river or into cesspools near town wells could contaminate the water supply, leading to a rapid spread of disease.

In August of 1854 Soho, a suburb of London, was hit hard by a terrible outbreak of cholera. Dr. Snows himself lived near Soho, and immediately went to work to prove his theory that contaminated water was the cause of the outbreak.

“Within 250 yards of the spot where Cambridge Street joins Broad Street there were upwards of 500 fatal attacks of cholera in 10 days,” Dr. Snow wrote “As soon as I became acquainted with the situation and extent of this irruption (sic) of cholera, I suspected some contamination of the water of the much-frequented street-pump in Broad Street.”

Dr. Snow worked around the clock to track down information from hospital and public records on when the outbreak began and whether the victims drank water from the Broad Street pump. Snow suspected that those who lived or worked near the pump were the most likely to use the pump and thus, contract cholera. His pioneering medical research paid off. By using a geographical grid to chart deaths from the outbreak and investigating each case to determine access to the pump water, Snow developed what he considered positive proof the pump was the source of the epidemic... Snow was able to prove that the cholera was not a problem in Soho except among people who were in the habit of drinking water from the Broad Street pump. He also studied samples of water from the pump and found white flecks floating in it, which he believed were the source of contamination.

On 7 September 1854, Snow took his research to the town officials and convinced them to take the handle off the pump, making it impossible to draw water. The officials were reluctant to believe him, but took the handle off as a trial only to find the outbreak of cholera almost immediately trickled to a stop. Little by little, people who had left their homes and businesses in the Broad Street area out of fear of getting cholera began to return.

From 1984 to 1996, multiple killings aroused public concern. The 1984 Milperra massacre was a major incident in a series of conflicts between various 'outlaw motorcycle gangs'. In 1987, the Hoddle Street massacre and the Queen Street massacre took place in Melbourne. In response, several states required the registration of all guns, and restricted the availability of self-loading rifles and shotguns. In the Strathfield massacre in New South Wales, 1991, two were killed with a knife, and five more with a firearm. Tasmania passed a law in 1991 for firearm purchasers to obtain a licence, though enforcement was light. Firearm laws in Tasmania and Queensland remained relatively relaxed for longarms. In 1995, Tasmania had the second lowest rate of homicides per head of population.

The Port Arthur massacre in 1996 transformed gun control legislation in Australia. Thirty five people were killed and 21 wounded when a man with a history of violent and erratic behaviour beginning in early childhood opened fire on shop owners and tourists with two military style semi-automatic rifles. Six weeks after the Dunblane massacre in Scotland, this mass killing at the notorious former convict prison at Port Arthur horrified the Australian public and had powerful political consequences.
The Port Arthur perpetrator said he bought his firearms from a gun dealer without holding the required firearms licence.

Prime Minister John Howard, then newly elected, immediately took the gun law proposals developed from the report of the 1988 National Committee on Violence and forced the states to adopt them under a National Firearms Agreement. This was necessary because the Australian Constitution does not give the Commonwealth power to enact gun laws. The proposals included a ban on all semi-automatic rifles and all semi-automatic and pump-action shotguns, and a tightly restrictive system of licensing and ownership controls.

Some discussion of measures to allow owners to undertake modifications to reduce the capacity of magazine-fed shotguns ("crimping") occurred, but the government refused to permit this.

Surveys showed up to 85% of Australians supported gun control,but some farmers and sporting shooters strongly opposed the new laws.