A Demonstration concerning the Motion of Light,
communicated from Paris

by Olaf (Ole) Roemer (1644-1710)
Philosophical Transactions of the Royal Society
No. 136; June 25, 1677

The diagram referred to in the translation appears on p. 234 of the French original, just below.

Demonstration tovchant le mouvement de la lumiere trouvé par M. Römer de l' Academie Royale des Sciences

December 7, 1676