Base Plate Compass, "every" part identified and explained

Here is a list of EVERY part and function on a standard Base Plate Compass.

I did an internet search this morning and there wasn’t one single website or video showing “every” part on a Base Plate Compass so I thought it would be interesting to make a video, so at least the information is out there.

This is a long video so if you want to fast-forward to a particular feature, here is the order they are described.  You can "click" the time to jump to that point in the video.

1. Direction arrow   3:20
2. Luminous pointer   3:50  
3.  Romer scales   4:15
4. Bezel/dial   5:35
5. Orienting lines   6:09
6. Ruler (imperial)   7:08
7. Magnetic needle   7:30
8. Risers   8:15
9. Lanyard attachment   8:50
10. Orienting arrow   9:15
11. Ruler (metric)   10:00
12. Declination scales   10:15
13. Index Mark / Line   11:35
14. Hole with crosshairs   12:10
15. Parallax Line(s)   12:50
16. Magnifier   14:10
17. Label holder   14:35
18. Sighting hole   17:20
19. Sighting mirror   18:10
20. Sighting Lines (H)   19:25
21. Sighting Lines (V)   19:40
22. Index Line   20:45


Here are the links mentioned in the video:
Take UTM coordinates /Grid reference with compass   UTM coordinates & grid references wit...
A simple method of dealing with magnetic declination   Magnetic Declination (very) simplified
Slope angle with and without an inclinometer   Slope angle with or without a clinometer