or REGIOMONTANUS, JOHN, a celebrated astronomer of the 15th century, was born at Koningshoven in Franconia in 1436, and acquired great reputation by publishing an abridgement of Ptolemy's Almagest, which had been begun by Purbach. He went to Rome to perfect himself in the Greek tongue, and to see the Cardinal Basilian; but finding some faults in the Latin translation of George de Trebizond, that translator's son assassinated him in a second journey he made to Rome in 1476, where Pope Sixtus IV. had provided for him the archbishopric of Ratibon, and had sent for him to reform the calendar. Others say that he died of the plague.

or Mullar, denotes a stone flat and even at bottom, but round atop; used for grinding of matters on a marble.—The apothecaries use mullers to prepare many of their tinctuous powders; and painters for their colours, either dry or in oil.

Muller is an instrument used by the glass grinders; being a piece of wood, to one end whereof is cemented the glass to be ground, whether convex in a basin, or concave in a sphere or bowl.—The muller is ordinarily about six inches long, turned round; the cement they use is composed of ashes and pitch. See GRINDING.