When British Scientists Fled from Mob Rule

Watt, Priestley and Withering

Three of the Lunar Society members who feared they would be attacked: James Watt, Joseph Priestley, and William Withering from left to right.

1789 was the year of the French Revolution.

Dr. Joseph Priestley wholeheartedly approved of the Revolution.

Priestley had discovered oxygen; invented fizzy, carbonated water; and had written what became the standard textbook on electricity for several decades.

Now he abandoned chemistry in favor of promoting the French Revolutionary slogans of liberty, equality and fraternity. He openly celebrated the abolition of the French Monarchy.

For his Revolutionary sympathies, he was criticized in the British Parliament. Meanwhile, the French Revolutionaries acknowledged their brother on the other side of the English Channel and awarded him French citizenship.

To celebrate the second anniversary of the Revolution, Priestley and other sympathizers planned a dinner in a hotel in Birmingham, England, where Priestley lived.

The French Revolution was popular at the time with a number of intellectuals in Britain. The infamous Reign of Terror, in which French Revolutionaries executed tens of thousands of people without trial still lay two years in the future.

Although popular with a minority of people, the general feeling in Britain in 1791 was hostile to the Revolution.

Priestley was warned that there might be violence at the dinner, so he did not attend it.

There was violence at the dinner, which spread to various locations, including Priestley’s home, which was attacked by a mob and burned to the ground, including his laboratory. Fortunately, Priestley had the good sense to have made himself scarce, and was not at the house to face the mob.

Priestley's House Torched by the Mob

Joseph Priestley’s house burning after being attacked by a mob.

Scientists, or as they were then called, Philosophers, became a particular target of the anti-revolutionary mob, whether the scientists supported the Revolution or not!

“No philosophers! Church and King forever!” was a favorite chant. The city of Birmingham was gripped by anarchy and fear.

With Priestley’s house destroyed, the mob looked for other scientists to attack.

James Watt, inventor, scientist, and father of the industrial revolution, and his business partner, Matthew Boulton feared they would be targeted. They fortified their engine factories and armed their workforce to defend the buildings from the mob. Their factories were not attacked, probably because most of the rioters were operating in other city neighborhoods.

Particular targets for the mob were members of Birmingham’s Lunar Society, who happily called themselves The Lunatics. The Lunar Society was made up of scientists, intellectuals and businessmen including James Watt, Matthew Boulton, Erasmus Darwin, James Keir, William Withering, and Joseph Priestley.

Joseph Priestley

The popular press portrayed Joseph Priestley unfavorably.

William Withering’s home was attacked.

Withering was a chemist and physician, who discovered the drug digitalis. Fortunately, the first port of call for the rioters who entered his house was his wine cellars.

While the mob fortified themselves with liquor, soldiers from the Fifteenth Light Dragoons arrived in the area. The mob got wind of the presence of the troops, and left the scene as quickly as their unsteady feet would carry them.

Other scientists in Birmingham, fearing for their lives, either fled from the city or lay low, hoping the rioting would be contained before the mob reached them or their houses or laboratories.

With riots continuing, King George III (Yes, he of The Madness of King George fame) finally gave into demands that troops should be sent to Birmingham to end the disorder. He is reported to have said: “I feel pleased that Priestley is the sufferer for the doctrines he and his party have instilled, and that the people see them in their true light.”

The riots had lasted four days.

Despite the sympathy of King George and other senior politicians for their actions, several rioters were hanged.

Priestley had the good sense not to return to Birmingham, but stayed in London, which was safer, although still uncomfortable. He and his family emigrated from London to the United States in 1794.


Shoemaker-Levy 20th Anniversary

Impact of comet with Jupiter

Image of Jupiter taken by Peter McGregor 12 minutes after an impact.

20 years ago, comet Shoemaker-Levy 9 made headlines around the world when it crashed into Jupiter. The impacts produced the biggest planetary explosions scientists have ever seen.

Astronomers were able to calculate that Shoemaker-Levy 9 had passed so close to Jupiter two years before impact that the giant planet’s powerful gravity had pulled the comet apart into fragments.

Shoemaker-Levy 9 Fragments

Shoemaker-Levy fragments flying through space two months before impact. Fragment G caused the explosion shown in the image page top. Hubble Image from NASA.

Don’t make the mistake that the word ‘fragment’ here means these were tiny particles. Three of the fragments were 1 km or more across.

This was a science story so big that it made headlines all over the world. The single explosion shown page top released the same amount of energy as a simultaneous detonation of 400 million Hiroshima sized nuclear bombs.

Jupiter’s clouds were left with dark scars where the impacts took place, which lingered for weeks.

Jupiter following the impacts. The dark patches caused by the impacts are almost Earth sized.

Jupiter following the impacts. The dark patches caused by the impacts are as big as planet Earth.

You can read more about the impacts on our Gene Shoemaker page.

So, What’s Been Happening Since?

Just last year, the Herschel Space Observatory captured this image, showing water in Jupiter’s stratosphere.

Water in Jupiter's Stratosphere

Image by ESA/Herschel/T. Cavalié et al.; Jupiter image: NASA/ESA/Reta Beebe (New Mexico State University)

A minimum of 95 percent of this water actually came from Shoemaker-Levy 9 when it vaporized in Jupiter’s atmosphere. The highest water concentrations are in the cyan/white areas of the image. The highest concentrations are in Jupiter’s southern hemisphere, where the comet struck.

Clearly, after 20 years, Jupiter is still feeling the effects of the comet impact!

But Wait, There’s More (Impacts)

Most of the scientists who were involved in the Shoemaker-Levy 9 observations felt they were watching a once-in-a lifetime event. However…

In 2009, astronomy enthusiast Anthony Wesley was imaging Jupiter from his backyard in Murrumbateman, Australia. A dark patch caught his eye, a patch which reminded him of one of the biggest astronomy stories he’d known in his life.

It looked very much like the scars he had seen on Jupiter from Shoemaker-Levy 9’s impacts.

Anthony Wesley quickly let the world’s astronomy community know what he had seen.

Telescopes around the world turned to focus once again on Jupiter.

And, sure enough, there it was… a new impact scar.

jupiter impact scar 2009

Jupiter scar from impact in 2009. NASA image from the Hubble Wide Field Camera 3.

Experience with the Shoemaker-Levy 9 impacts allowed astronomers to estimate the object that hit Jupiter in 2009 was a few hundred meters across.

So what else does the 2009 impact tell us?

The 2009 collision means that:

Either impacts are much more frequent than astronomers thought. Most astronomers thought there wouldn’t be another major impact on Jupiter for hundreds of years…


We’ve been lucky to see such rare impact events twice within the space of 15 years.

I don’t know about you, but personally, I’m hoping it’s the latter of these two possibilities!