A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: John D. Howard
Date: 2016 Mar 28, 08:14 -0700
A book that talks about early navigation in baloons and Zepplins is " Most Probable Position" by Monte Wright. In it he describes sextants with bubble levels - marine sextants with an artifical horizon - that were tried in baloons in the late 1800's and German Zepplins during WW1.
I have bought several so-called baloon sextants on e-bay. They are misslabled by the seller. The correct term is Pibal - pilot baloon transit. The instrement looks like a theodolite or transit but the eyepiece is at 90 degrees to the objective lens. The eyepiece is in the horsontian axis. You can keep the baloon in sight even if it flys overhead.
There is a Navy model for use on ships that looks something like a big - heavy sextant but is monten in gimbles.
Hope this helps.