Me: Ed, do you have a ruler?
Ed: No, what do you need to measure? I can eyeball most things within a 16th of an inch. How about you John?
John: I can usually guess within 30 thousandths.
Me: Bullshit! How thick’s your nameplate?
John: *closes one eye* Hm… about 125 thousandths. A little less.
Me: To the micrometer! *gets micrometer*.
John: So what was it?
Me: 118 thousandths.
Ed: Impressive, but I can identify screw gauges at a distance of 10 feet.
Now I know what my engineering challenge will be next week.