Hartog 'Hatta' Knoop ran a diamond-cutting business in his kitchen at home. When the stock market crashed in 1929, Hartog Knoop lost his modest fortune because he had invested it in German marks.
Hartog Knoop was a rather reserved, warm-hearted man. He had the habit of peeling apples and eating the peel, giving the apples themselves away to children. Since he wanted his two daughters to learn a tr…