Building of the Twelve Collegiums (Spb State University) — On Vasilievsky Island in Saint Petersburg, Russia Photo Credit: By A.Savin (Wikimedia Commons · WikiPhotoSpace) - Own work, FAL, https://commons.wikimedia.org/w/index.php?curid=84369599
The Old Observatory of Tartu Observatory — Completed in 1810. Friedrich Georg Wilhelm von Struve worked here. Photo Credit: By BigFlyingSaucer - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=20206740
Diagram of Faraday's iron ring apparatus — The changing magnetic flux of the left coil induces a current in the right coil Photo Credit: By Eviatar Bach - Own work, CC0, https://commons.wikimedia.org/w/index.php?curid=16608674