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Turns out the bottom eyepiece is an optical plummet as some suggested. If anyone figures out the the top item, I'd appreciate it. Thanks for the help so far.
The top arrow points at what I think is a hole for electrical lighting. It will either illuminate the scales or the cross hairs or both. The eyepiece... I
I posted a picture of the Theodolite in the Photos section with two red arrows showing the parts I'm interested in learning about. The bottom arrow is the
... It looks to me that it is the optical plummet. When yoy mount it on a tripod you will see the ground through it. It serves the same purpose as a normal
I've got a picture at: http://www.iowasurveyor.com/junk/topcon-arrow.JPG I drew an arrow to what I think you may be asking about. If it's not, then sorry. I