Calculateur de Parallaxe / Parallax Berekenaar (Parallax Calculator) PB4Y Privateer Measures ~ 4 inches diameter

Measures ~ 4 inches diameter and 3

plus the spares

25 inches diameter and ~ 2

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

Calculateur de Parallaxe / Parallax Berekenaar (Parallax Calculator) PB4Y Privateer Measures ~ 4 inches diameterWe 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