n. [ Cranium + -meter. ] An instrument for measuring the size of skulls. [ 1913 Webster ]

n. [ L. radius radius + -meter: cf. F. radiomètre. ] 1. (Naut.) A forestaff. [ 1913 Webster ]

2. (Physics) An instrument designed for measuring the mechanical effect of radiant energy. [ 1913 Webster ]

☞ It consists of a number of light disks, blackened on one side, placed at the ends of extended arms, supported on a pivot in an exhausted glass vessel. When exposed to rays of light or heat, the arms rotate. [ 1913 Webster ]