Convert grad Newton to réaumur

Before Celsius won out, each country had its own thermometer. Réaumur (1730) put water's freezing point at 0 °Ré and its boiling point at 80 °Ré; the scale was standard in France, Germany and Russia through the 19th century and survives in a few Alpine cheese dairies. Delisle (1732) ran backwards, 0 at boiling and 150 at freezing, and was used in Russia for about a century. Rømer's scale (1701) has freezing at 7.5° and boiling at 60°, and Newton's (1701) freezing at 0 and boiling at 33.