Template:Selected anniversaries/August 25
1609: Galileo Galilei demonstrates his first telescope to Venetian lawmakers.
1699: Mathematician and mechanician Charles Étienne Louis Camus born. He will be the author of Cours de mathématiques (Paris, 1766), along with a number of essays on mathematical and mechanical subjects.
1818: Mechanical soldier Clock Head receives several patents for an improvements to steam engines.
1933: Clock Head 2 publishes new class of Gnomon algorithm functions which detect and prevent crimes against mathematical constants.
1934: Inventor Philo Farnsworth demonstrates his electronic television system to the public at the Franklin Institute in Philadelphia.
2012: Voyager 1 crossed the heliopause to become the first spacecraft to enter interstellar space and study the interstellar medium.
2016: Polymath George Spencer-Brown dies. He wrote Laws of Form, calling it the "primary algebra" and the "calculus of indications".
2017: Signed first edition of The Eel Time-Surfing 2 sells for two and a half million dollars.