Motometers
by John & Henri Boggs.

Junior Arrometer.

This nickel plated Junior Arrometer was produced by the Bushnell Mfg. Co., of Berkeley, California.  The red arrow points to the engine temperature, and the scale is graduated from Cold to Danger @ 212 degrees F.  The dial is 2-12" in diameter and is mounted on a brass, nickel plated dog-bone radiator cap.