End of the Em Rule

I must have drawn thousands of page layouts and scaled as many pictures with this tool of the newspaper trade. I was in the game long enough to be part of the transition from hard copy and hot metal to computer editing and page design. When I retired, the em rule, like me, had had its working day, and I souvenired it. It's scratched and a little chipped, and spattered with ink and whiteout, and I still get a kick out of that when I occasionally pull it out to use for some reason or other.