On November 28, 1660 a group of 12 friends in London decided their weekly meetings to discuss experimental science needed a more formal structure. This group of amateurs elected temporary officers, prepared a set of rules, agreed to a membership fee (one shilling per meeting), and proposed a tentative list of 55 members. Two years later Charles II granted a charter to the Royal Society of London for the Promotion of Natural Knowledge. The mace as granted by the King continues on display today and is presented at the ceremony when new members sign the book using a quill and ink just as at the original gathering in 1662.
The "Invisible College" - Robert Boyle's name for the group of 12 friends.