1. The Abney Level Useful for simple slope profiles, horizon diagrams and height measurements
Level bubble
Rotating Arm
Eyepiece
Scale (in degrees)

2. The Abney Level View Through The Eyepiece
Viewing side
Rotate arm to align Level bubble
Align bubble with this line
Target eg staff
Mirror side

3. Slope Profiling Slope distance Equal length poles Measured angle 
Abney level
Equal length poles
Slope distance

4. Useful Notes For Profiling
Take measurements at changes in slope and at points of interest (eg swampy areas, erosion sites etc)
Follow the line of steepest slope (this will mean your line is not straight) – but do avoid dangerous slopes or cliffs
Try to keep the staffs vertical when measuring
Take care when winding the tape measures or they will jam or break
Use tape to measure slope distance
Use Trig to calculate horizontal and vertical distances for plotting cross sections

5. Horizon Diagrams
Used at specific sites to quantify the shape of the horizon
When matched with sun path, gives indication of possible light levels at a site (therefore susceptibility to frost, suitable plants for a site etc)
Can be a useful way of considering how topography may affect wind patterns

6. Horizon Diagrams Centre rep. Straight up, ie 90o elevation
Outer ring rep. horizon
000o
315o
045o
270o
090o
Azimuth = 270
Elevation = 030
225o
135o
180o

7. Measuring the height of a tree
Measured angle 
Abney level
hpole
Measured distance (d) eg 20m
Hint: use a larger distance for a taller tree to make things easier
Htree = hpole + (tanθ.d)