Ole Rømer - Danish astronomer - the velocity of light

 

https://www.britannica.com/biography/Ole-Romer

Rømer explained that the speed of light was such that it takes light 22 minutes to cross the diameter of Earth’s orbit. (Seventeen minutes would be more accurate.) 

Title: Cassini, Rømer, and the velocity of light

https://adsabs.harvard.edu/full/2008JAHH...11...97B