Calculateur de Parallaxe / Parallax Berekenaar (Parallax Calculator) PB4Y Privateer

Calculateur de Parallaxe / Parallax Berekenaar (Parallax Calculator) PB4Y PrivateerWe frankly have no idea exactly in which specific application this Parallax Calculator was used (aeronautical or astronomical or ?). This large device measures ~13 inches square and has 3 clear disks and 1 clear arm that rotate around a center axis affixed to a metal rimmed wooden base board with what appears to be measurements of deflection. The disks may be secured by turning the 4 metal knobs. It is labeled in French and Dutch. A cool piece

plus the spares

The watch will not wind and requires service by a qualified watchmaker

(c) aural reception of modulated or unmodulated radio frequency energy using a loop antenna (d) aural-null directional indications of the arrival of modulated or unmodulated radio frequency energy using a loop antenna

This aligns with the total fuel capacity of the B-52 B

Measures ~ 4 inches diameter and 3

Both have operating ranges painted on the glass for the last aircraft in which they were installed

If it were a Nose angle indicator

and the right dial is labeled with the Japanese character for "Thousands"

This has been confirmed in the F-80 Illustrated Parts Manual dated 1958

25 inches diameter and ~ 2

The pressure tubes have been bent sideways for an unknown reason

so theoretically it's possible that this was used in a Boeing bomber B-50 Superfortress (developed from the B-29) which was in service during this period