Saw this lovely, if slightly knacked, adding machine in the Sun Inn, in Morpeth. You stick a stylus (or a finger) in one of the holes and drag it down to add to a column. It was a bit rusty and skipped digits more often than not.

@christianp If you have a carry do you pull the column up and "hook over the top"? I have one of these on the back of a slide rule - it's called an "Addiator".

@ColinTheMathmo no, it does it for you. There must be something like a notch on the side of each digit drum, to catch the next one along. The columns you pull down are on springs, too.
I've got a Correntator, which I think is the (old-) money equivalent of your addiator

@christianp Ha! I'll have to pop in and have a look :)

A Mastodon instance for maths people. The kind of people who make $\pi z^2 \times a$ jokes.

Use $ and $ for inline LaTeX, and $ and $ for display mode.