Short answers, pulled from the story.
The Lunar Society took its name from the full moon. Members scheduled their meetings to coincide with the full moon so that the moonlight would make their journeys home safer and easier in the absence of street lighting. The name "Lunar Society" first appears in written records in 1776.
Fourteen individuals have been identified as having attended Lunar Society meetings regularly over a long period. These include Matthew Boulton, Erasmus Darwin, James Watt, Joseph Priestley, Josiah Wedgwood, William Withering, William Small, Richard Lovell Edgeworth, Samuel Galton Jr., Thomas Day, James Keir, John Whitehurst, Jonathan Stokes and Robert Augustus Johnson.
The group that became the Lunar Society began forming in the late 1750s, and historians date its establishment anywhere from before 1760 to 1775. The first meeting under the formal "Lunar" structure was probably held on the 31st of December 1775. The society definitively collapsed by 1813, when Samuel Galton Jr. won a ballot for the scientific books from its library in August of that year.
William Small was the central figure who transformed a loose circle of friends into a coherent group. A Scottish physician who had previously taught Thomas Jefferson at the College of William and Mary in Virginia, Small arrived in Birmingham in 1765 with a letter of introduction from Benjamin Franklin and immediately became the key link between members. His death, probably from malaria, in 1775 prompted the remaining members to place the society on a more formally organised footing.
The Priestley riots of 1791 dealt the society a decisive blow. Joseph Priestley was driven from Birmingham and left England for the United States in 1794. William Withering's home was invaded by rioters, and Matthew Boulton and James Watt had to arm their workers to protect the Soho Manufactory. Although a younger generation of members' family members kept meetings going into the nineteenth century, the collaborative spirit that had defined the society's heyday was noticeably absent afterwards.
A new Lunar Society was established in Birmingham by a group led by Dame Rachel Waterhouse, with the aim of contributing to the development of the city and its wider region. Clive Stone was elected Chair of the society in July 2023, and the society was still operating in 2024.