A collection of art from Bertram and Diana Firestone's home at Newstead Farm in Loudoun County, Virginia are currently being offered during a week-long online auction, hosted by Sotheby's. The auction, which runs from Sept. 1-9, features nearly 70 works from their personal collection. Among the choice lots included in the web auction are a series of portraits highlighting the Firestones' passion for a variety of equestrian pursuits, ranging from racing to hunting and steeple-chasing. Included among the highlights of collection is Peter Curling's Sprint Finish and Peter Biegel's Red...