The first LORAN receiver for aircraft use to enter service.
An astrodome provided an enclosed area from which a navigator could take sightings.
One of the first effective models of bubble sextant for aeronautical use.
A maritime sextant with a special bubble attachement to the eyepiece to aid in establishing a horizon in aeronautical use, circa 1919.
This forerunner of the ubiquitous E-6B flight computer was prominent in the five years before World War II.