NEW YORK.- As part of Old Masters Week, Sotheby’s New York will offer Heidelberg with a Rainbow (est. $4/6 million) in their Important Old Master Paintings and Sculpture sale on 31 January 2013. Heidelberg with a Rainbow was commissioned from Joseph Mallord William Turner by the engraver Thomas Prior in 1840, and the impressive sheet belonged to several of the most important 19th century collectors of the artist’s works, including Joseph Gillott and Sir Donald Currie. The work stands out as one of the crowning achievements of the artist’s mature style, combining his unique use of sweeping passages of hazy color and light with his acute draftsmanship in the rendering of figures and architecture. Photo: Sothebys.