NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Adrian F
Date: 2019 Mar 11, 10:51 -0700
David,
The questions around the Appleyard computer are interesting. I’ve found these references if any use to you :
A description of the use of the “arms” of the computer in a 1922 report (page 22-23) :
https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19930091194.pdf
A brief article in “Flight” magazine of 14 January 1937 described a further use for the arms, and indicated how the “Appleyard scale” could be used to roughly convert indicated air speed to true air speed. I couldn’t glean from that any reason for the discontinuous scale. The article is in the Flight magazine archive hosted by Flightglobal:
https://www.flightglobal.com/pdfarchive/view/1937/1937%20-%200100.html
I see that the Imperial War Museum in the UK holds a 4-page document from 1918, “Description and use of the Air Speed Computer designed by Commander Rollo Appleyard R.N.V.R.”, its listing is at :
https://www.iwm.org.uk/collections/item/object/1504002019
Adrian
