ROYAL ASTRONOMICAL SOCIETY / SCIENCE PHOTO LIBRARY ROYAL ASTRONOMICAL SOCIETY / SCIENCE PHOTO LIBRARY
Century calculating machine. Diagram of a calculating machine designed by J. Rowning. Image from 'Directions for Making a Machine for Finding the Roots of Equations Universally, with the Manner of Using It: By the Rev. Mr. Rowning, to John Bevis', published by J. Rowning, on 1st January 1770.
Model release not required. Property release not required.