Accelerometer, G-Meter, Type B-4, 0-9+ G's, Bendix, Boeing B-47A Bomber
This electrical aircraft Accelerometer (aka G-Meter) is a Type B-4, part number 3416-3A-A1, made by Bendix for an order by the US Air Force dated 1949 (see serial number prefix). The knob rotates a small indexing pointer around the perimeter of the dial (sitting at 5 G's in the main photo), which may be a limiter or a trigger for a warning indicator. This accelerometer is clearly intended only for aircraft expected to experience positive G's as there is no negative G scale.
An accelerometer with an identical face appears in the Oct 1950 flight manual of the Boeing B-47 A Stratojet Bomber (see photo).