February 1860 Rome
[...] I will mention to you a bassorilievo which would do for your rotunda among the classical statues. It represents Eteocles and Polynices going to fight a duel whilst their mother Jocasta is between them endeavouring to pacify them. Several years ago when Marshal Marmont came to my studio when he stood before this bassorilievo he said that it was the finest thing which I had done. Such works might be executed in the grey marble which costs less than half of the statuary. Thorwaldsen executed some of his fine bassorilievi in the grey marble for Prince Torlonia, for the palace. I have other models for bassorilievo such as the one representing Minerva giving the winged horse Pegasus to Bellerophon. [...]