phil.p":1dzn210j said:
Inspector":1dzn210j said:
Work had a 10 foot Mitutoyo but it was a true vernier calliper, not digital. it was a two person job to use. :wink: Once over 40" or so you usually need help to measure things
Pete.
I spoke to an old guy one day who told me he was part of the team that cleared out the old Holman's workshop in Camborne when it finally closed down (they made large scale mining equipment).
They found a 108 inch micrometer. How accurate/inaccurate it was who knows? :?
I'd hazard a guess it was for surveying movement in mine works e.g. height of a tunnel. Accuracy wouldn't matter too much as long as it precisely measured any change in height at chosen spot points, and you used the same bit of kit. Just a guess.
Surveyors do something similar by attaching a calibrated sliding scale over a gap to see if it moves. Or simpler - attach a slip of glass, which will break if there is any movement.