NavList:

The discussion of the Brown-Nassau CN Plotter brought to mind the following question. What methods did the early pioneers of trans-Atlantic flight use for navigation, such as Alcock and Brown?  Brown was the navigator on that flight.  They made landfall near their intended destination.  Running down a line of latitude would be a clear choice, but how measure the latitude?  They flew at low elevations, so perhaps using the actual horizon?  Dip scales as the square root of elevation.  The error for being 50 feet off in elevation is less than two minutes of arc at 200 feet.  In contrast, Admiral Coutinho installed levels on his Plath in 1919.  Had the British?  Then there is RDF, which was available in the U.S. by the Point Honda disaster.

Those are some guesses.  What does the documentary evidence say?

Thanks.

Fred Hebard
mbiew---.net