The train club meets on Tuesday night and I'm presenting a clinic on railroad grades. This all started when I was looking at a cheap 12" aluminum level I picked up at the dollar store. It has three bubble levels: horizontal, vertical, and forty-five degrees.

Since each of the bubbles is held in place with two screws, I got to thinking that I could adjust them to show one, two and three percent grades.

That began the quest to complete all the computations and find an easy way to do all the calibrations. So here it goes:

- 1% grade is 1" of raise over 100 inches distance.
- One inch divided by 100 inches is 0.01 inches.
- 100 inches is 8.33 feet.
- 0.01 times 8.33 is .083 inches of elevation per foot for a 1% grade.
- A Kennedy Half Dollar is 0.084 inches thick, which is pretty damn close to 0.083".

So, with a foot long level, you set one end on top of one coin and adjust the bubble so it says level. Do it over two coins and adjust one of the other bubbles to level. Lay it on three coins and adjust the last bubble to level. Finally, label the bubbles for one, two and three percent grades.

Now, as I'm doing the subroadbeds, I can refer to the level to make sure I don't exceede my layout standards.