NavList:

David,

I do have the book and a whole chapter is on balloon navigation.  As I said in an earlier post the balloon pilots used a marine sextand with a bubble artifical horizon.  Other ways were used:  plumb bob, gyro stablized,and even bowls of mercury but the bubble was most common.

The sight was the same as at sea.  Reducing the triangle with sin-log tables and map plotting.  A pain to do but dooable.In 1905 one person used the sextant and fixed his position and another looked down at a landmark.  They were about 10 mi. diference.  This was considered good enough. ( in 1977, flying the Pacific 10 mi. was OK also )

Cel nav was not too important to balloons because they rarely went ofshore.  The biggest problem was a lack of maps.  Maps were not printed for a balloon point of view so getting landmarks - railroad tracks, water towers, dams, etc. onto a map was more important.   When the Zepplins started bombing England in WW1 they did so above an overcast sky so cel nav again became important.  They used marine-type sextants with bubble AH and did the reduction and plotting as a ship would.

John H.