But seriously, gauge blocks are fascinating; as are fine micrometers. Changes in temperature causing expansion drives home the inexactness of size. At certain scales it all becomes relative.
I used to work in this one factory where I had use to calipers for making sure parts were within specification, and they were digital calipers. Which are all fine and good, except the ones they had sucked. Really made me appreciate the value of a good, old-fashioned well-made analog caliper.
I just spent my afternoon doing volume calculations... each unit is 3 oz, I need 300 units, 900 oz, but I can only buy in 1 gallon which is 128 oz, etc. For this one, each unit is 10g and 600 of those, I can buy in 1.25 lb or 2.6 lb let's convert that and see what the cost per gram is and go with the cheaper, okay I can buy in 1180g how much do I need again?
Repeat that 57 times and you too can have a job in supply chain.
If [I buy wheat] at Wrexham, [I must order] by the hobbet of one hundred and sixty eight [pounds] [76 kg]. But, even if I do happen to know what a hobbet of wheat means at Wrexham, that knowledge good for Flint is not good for Caernarvonshire. A hobbet of wheat at Pwlheli contains eighty-four pounds [38 kg] more than a hobbet at Wrexham; and a hobbet of oats is something altogether different; and a hobbet of barley is something altogether different again.