Indeed, as if no circumstance in the confirmation should be wanting, the diameter of the planet, as measured by the micrometers at Berlin, proved to be practically coincident with that anticipated by Le Verrier.
"The Story of the Heavens"
Robert Stawell Ball
The difficulty in the process arises from the fact that these ellipses are so small that our micrometers often fail to detect them.
"The Story of the Heavens"
Robert Stawell Ball
We now fixed the micrometers to the telescopes, and observed or measured the uneclipsed part of the sun's disk.
"A General History and Collection of Voyages and Travels, Volume 16"
Robert Kerr