English: diagram, where A B representeth the object metall, C D the eye glass, F their common Focus, and O the other focus of the metall, in which the object is placed.
Public domain works must be out of copyright in both the United States and in the source country of the work in order to be hosted on the Commons. If the work is not a U.S. work, the file must have an additional copyright tag indicating the copyright status in the source country. Note: This tag should not be used for sound recordings.PD-1923Public domain in the United States//commons.wikimedia.org/wiki/File:Philosophical_Transactions_-_Volume_006_-_p3080.png
Captions
Add a one-line explanation of what this file represents
Uploaded a work by The Royal Society of London from https://en.wikisource.org/wiki/Page:Philosophical_Transactions_-_Volume_006.djvu/306 with UploadWizard