Cox and Stevens
Intercept Officers Equipment Kit, Type I (Navigation Computer) 1943
This is a WWII-era navigation computer in a kit "Intercept Officers Equipment Type I. This example includes two 2-piece USAAF Ground Speed Timer Calculators (for map scales 1:250,000 and 1:500,000) and 2 USAAF Rulers.
The bottom of the metal case contains a mechanical computer to solve the wind problem. It has a locking mechanism and a movable arm for drift, adjusted for air speed, interconnected to the heading tracker. The lid contains tables and a calculator for speed or gals/hr. A pretty cool device.
The case measures ~ 12 in x 5 in x 1.5 in. Its is in very good condition given its age.