Blaise Pascal's Calculating Machine (1645)

This is but one small part in the larger work on the history of Babbage's Analytical Engine:

https://www.fourmilab.ch/babbage/

This is honestly a really great work of historical research; if it were a book, I'd purchase a copy to add to my collection on Babbage and his works (small tidbit: Babbage is also the inventor of the "cow catcher" on trains).

Reading this, along with other books about the period (and contemporary with the period), one quickly comes to the determination that for all the fantasy aspects of the Steampunk genre, it doesn't hold a candle to the actual period of time (especially if one considers the idea that centuries "bleed" into each other, and allows for the early Edwardian period to be a part of the "Victorian-era" whole).

The article on Wikipedia, https://en.wikipedia.org/wiki/Pascal%27s_calculator, looks like a much better link to me.

The following other mechanical calculator also seems to be an important step: https://en.wikipedia.org/wiki/Arithmometer