spoiler
For people that don’t know this is not how you use Calipers
“Caliper jaws for inside measurement—I thought of that. Turned out it already existed, but I arrived at it independently."
I think the guy was actually referring to something a bit different, that is having a second number scale on the caliper that is offset by the width of the first jaw, so you can use the outside jaws for measuring inside dimensions. I don’t think that would work, however.
I was indeed (and I think you’re right, the calipers would need at least to be parallel on their outer edges to work this way).
I’m not sure what rz2000 was doing by (slightly wrongly) rewording basically what I wrote — I get the impression they think I was being full of myself for thinking of a (similar) concept that already exists (despite conceding that it already might) and felt the need to put me back in place.
No, I think you correctly identified the shortcoming with the tool if it were only usable for outside measurements. It does turn out that your idea was already implemented, but it is nevertheless a good idea.
The wording however is an echo of a line from Mad Men, where Pete Campbell is talking about coming up with the idea for direct marketing: https://www.youtube.com/watch?v=a05WUtLZfU8
The second scale sounds like a good Idea till you mess up everything due to using the wrong one. I once had a Spirit Level that was for plumbers and had a Second bubble-level built in that was even when the Level was tiltet to about 1.5 degree, great for waste-lines and gutters. Now everything in my House ist tilted by 1.5 degree except the plumbing and gutters.
