History 4-5

This is one of the best all around sites that I have found. It is titled “The MacTutor History of Mathematics Archive.”
http://www-history.mcs.st-and.ac.uk/~history

This is an award-winning site that links to all sorts of mathematics information.
https://mathshistory.st-andrews.ac.uk/HistTopics/History_overview

Here is a history of mechanical calculators with pictures and links:
http://www.xnumber.com/xnumber/mechanical1.htm

Napier’s Bones is an example of a 17th century calculating device:
http://gwydir.demon.co.uk/jo/numbers/machine/napier.htm

Napier:
https://mathshistory.st-andrews.ac.uk/Biographies/Napier

Babbage:
https://mathshistory.st-andrews.ac.uk/Biographies/Babbage

Hawking:
https://mathshistory.st-andrews.ac.uk/Biographies/Hawking