At my old job, when one of the engineers retired, he would ceremonially dump everything they had in their office onto a table in the hallway for the rest of us to pick over like vultures. The coolest thing I ever found was something called a Gerber Variable Scale.
The variable scale is a stretchable spring with markings at regular intervals. When you stretch the spring, the markings change size. The tool is made for transferring markings off graphs without well laid out axes. You can also draw neatly delineated tick marks with it as well, at any size you want! Pretty cool!
In the picture below the spring for the scale is compressed all the way. The little disks are numbers, but most of them seem to have fallen off over the years.
The variable scale has marking for reciprocal, linear, and logarithmic values. It makes it possible to execute some pretty crazy transformations if you want to make a logarithmic graph.