The lady vanishes (or, an adventure in connoisseurship)

Matilda started it all. Towards the end of 2008, Sotheby's Australia's Sydney office had consigned for sale from the UK two quite extraordinary works of Australian colonial art: Campbell's Wharf, one of the very finest of Conrad Martens' harbour watercolours, and a late 1810s sketchbook by the pioneer woman artist Sophia Campbell. The sketchbook in particular was a real treat, and something of a gift for a hard-pressed auction house researcher; it (and a closely related sketchbook in the National Library of Australia) had been thoroughly documented in the early 1980s by the distinguished colonial art historian, Professor Joan Kerr, and now featured in numerous standard reference texts.