August 30: edit
- 1831 - At his father's bidding, Charles Darwin penned a letter to August Henslow, declining the offer of a supernumerary position aboard the HMS Beagle, which was then being prepared for its second voyage. He would change his mind and accept the offer the next day.
- 1910 - Carlos de Paula Couto was born in Porto Alegre, Brazil.
- 1918 - Samuel Wendell Williston died in Chicago, Illinois, USA at age 67.