Jacob Spornberg ( 1768 - 1840 ) was a British painter. Jacob Spornberg s works have been put up for auction numerous times, with realized prices surpassing estimated prices, varying from 172.21 USD for Portrait of a young man, to sinister in 2004 to 688.23 USD for A silhouette of an Officer in 2005 , based on the size and medium of the artwork.