Vernier (EB)

A grey cold day of odd jobs, so as one of them involved measuring part of my bicycle I have blipped the vernier gauge I used.

Made in Czechoslovakia, so it predates the Czech Republic (1992?) and is probably much older.   They are still made and now often available with a digital readout, these make life easier.  The pre-digital versions are not too difficult to read, and like the slide rule, having to think about the expected result first often leads to a better outcome.  This YouTube video explains how. Age impaired engineers may need to find their reading glasses though :-)
See extra too for the reading.

In other news, we heard some tapping sounds from the des res nest box I cleaned out last weekend - didn't see what it was so I have set up the camera trap in the hope of finding out.