Mitutoyo: The Origin and Evolution of Calipers - PDF and photo

[Jon]

They go from 'caliper' to 'calliper' so many times I had to stop reading and just scanned through the rest of the document looking at the pictures.

Two letter L's in caliper is the British spelling. But yes, I'm a fan of "pick one spelling and stick with it."

Considering Mitutoyo's extraordinary reputation, I'm happy to stick this one in the "highly adept technical people who make dumb spelling and grammatical errors" drawer.