Interferometer
an astronomical instrument invented by Prof. Albert A. Michelson and used in measuring the diameters of stars. By its application on the great Hooker telescope of Mount Wilson Observatory the diameter of the star Betelgeuse was recently ascertained to be 300 times the diameter of the sun. (See BETELGEUSE, Vol. II.) INTERNATIONAL COURT. (See PERMANENT COURT OF INTERNATIONAL JUSTICE.) INTERSTATE COMMERCE. (See UNITED STATES: RAILWAY RATE DECI- SION.)