Quote Originally Posted by Nexis View Post
Hmmm. How about using mercury? Far more stable than water. Maybe the plate could be magnetic and point to North to mark your bearings, then read the shadow length.
I think a wrist version would be too small for serious navigation. You would need a much larger plate to get an accurate distance reading.
I'm in agreement with all of that! I'm sure natives figured out how to mine mercury as early as humans ever did. I totally agree with the need for larger tools for precise navigating, was already thinking that to myself too... Some trips might not need as much so varying levels of size and quality would likely be seen. For any version that did use a glass bauble and an air bubble, would water scatter light and dim or affect the shadow? I guess that could be calculated for... Though convenient versions might still use a bed of oil or mercury, just because trying to hold it level yourself could be a little annoying, since it could be a big deal if you're off even a little bit.