or Regiomontanus, John, a celebrated astronomer of the fifteenth century, was born at Konings-hoven, in Franconia, in 1436, and acquired great reputation by publishing an abridgment of Ptolemy's Almagest, which had been commenced by Purbach. He went to Rome to perfect himself in the Greek tongue, and to visit Cardinal Bassarion; but finding some faults in the Latin translation of George de Trebizond, the translator's son assassinated him in a second journey which 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. But others state that he died of the plague.

Mullor, denotes a stone flat and even at the bottom, but round at the top, being used for grinding substances on a marble. The apothecaries use mullers to prepare many of their testaceous powders; and painters for their colours, either dry or in oil.

Muller is also an instrument used by the glass-grinders, being a piece of wood, to one end of which is cemented the glass to be ground, whether convex in a bason, or concave in a sphere or bowl. The muller is commonly about six inches long, and rounded by turning; the cement Mullingar used is composed of ashes and pitch.