Microscopic Writing
The online Small Worlds exhibition at the Museum of the History of Science features this microscopic writing machine, created by banker William Peters in 1862: "The machine was occasionally brought out at Microscopical Society soirées to write the Lord's Prayer and to draw geometrically."
They also liked to write tiny, boasting letters - "I trust you will agree with me that there are other small things to be seen in London besides Tom Thumb":
