Extending the range of calipers

[mklotz]

This is unusual way to extend the range of a caliper...

A variation of an old dodge used to measure where obstructions or the lack of a sufficiently long ruler prevent direct measurement. An example would be measuring the distance between two parallel walls spaced somewhere between 12 and 18 inches apart when all you have is a 12" and 6" ruler.

Useless for accurate measurement of a diameter unless you have some other way of ensuring the calipers measure along a diameter.