Images labelled 'Bush portrait 2' and 'Differential Analyser - Close-up' are used courtesy of MIT Museum - more images available at: MIT Museum Collections - People.

All other images are believed to be public domain. If you believe you own the rights to any image, please contact me and the image will be either accredited or withdrawn.

If you wish to use a public domain image on another Web site, please feel free to so without any further permission.