Lot 156: 

John S. C. Schaak (fl. 1760-1770)
Portrait of a young boy, traditionally identified as James Mendam, full-length, in a satin waistcoat and blue coat, holding a book in his right hand, beside an urn on a plynth, in a landscape
signed and dated 'JSC Schaak.pinx.176*.' (lower left)
oil on canvas
50 x 34½ in. (127 x 87.6 cm.)

Anonymous sale; Christie's, London, 24 April 1987, lot 86.