I have always found it amusing that telescope apertures are specified in inches (pretty well universally) and eyepieces are either 2" or 1 1/4" but the focal length is always in mm! Even in the US!!
In the late 70's I worked in a place where the clerical assistant had a "decimal clock". It had 12 hours, but had decimal minutes. When you did your timesheet you had to fill it out in decimal hours. So you started at 8.5 and had lunch from 12.5 to 1.25, finishing at 4.5 for a total day of 7.25 hours. It made her job easier by making it harder for the other 20 staff. Many would constantly start work at 8.3 and take lunch from 12.3 to 1.15, knocking off at 4.3 giving a total day of 7.15 hours....
Making it hard to work up a "flex day".
Around 1966 my parents owned a milk bar and they had a number of customers come in complaining about the new decimal system. A few of them said "why can't they just wait until all the old people have died and introduce it then?"
