Inclinometer, pen and paper
Before starting on the hike up have the students use an inclinometer to measure the angle of the incline. To use the inclinometer the student should look through the cylinder at the object they are trying to get an angle on. In this case they might use the engine house (or from the engine house use the skew arch bridge). Their partner should look at the string and determine what angle (or number) the string is crossing. Make sure your inclinometer is oriented so the edge that has the cylinder flush with your card is away from you. Do the set-up for "Change in Elevation" here, also make sure ehy write the angle down, you'll need it it determine the change in elevation.