Battenberg Course Indicator Mk 5 in Wood Case Wellington and P-38 Lightning

and P-38 Lightning

The compass was illuminated electrically via bulb mounted in a small compartment over the compass itself

but cannot directly calculate where a projectile will land because it has no input for velocity or ballistic coefficient

and presents it to the pilot visually on the Zero Reader Indicator

569432" and  "General Electric Canada"

Battenberg Course Indicator Mk 5 in Wood Case Wellington and P-38 LightningHere is an original naval Battenberg Course Indicator Mk 5. The Battenberg course indicator is a mechanical calculating device invented by Prince Louis of Battenberg in 1892 for taking station on other vessels whose range, bearing, course and speed are known. By extension, it has a range of other functions related to relative velocity calculations. A number of versions of the device were produced and it proved particularly useful for station keeping,