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 with a c...  
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