For WHBM Post 114 etc,
The 707-436 had the Kelvin Hughes Sextant. The 707-336 had the Kollsman Sextant and for Polar Nav, also carried the Kollsman Sky Compass – for when there were no stars. Descriptions below.
There were only about 20
BOAC Approved Stars, plus Sun Moon Venus.
Anything else in God's Firmament was wholly unapproved for
BOAC Navigation and would get you an interview with the Nav Office God.
Black Art indeed. LFH