We are grateful to Dr. Sam Segal for confirming the attribution to van Aelst on the basis of a transparency (private communication, 7 September 2000). He has suggested a dating to 1648-49 and notes the presence of a similar marble ledge in a number of signed works by the artist, including one from 1648 (catalogue of the Galerie Pallamer, Vienna, 1990, no. 1) and another from 1649, with Galerie Roelofsz, Amsterdam, 1995, reproduced in Bergström, 1956, fig. 183 (as dated 1646).
Mr. Fred Meijer, of the Rijksmuseum voor Kunsthistorisches Documentatie, The Hague, rejects the attribution to van Aelst and has suggested an alternative attribution to Pierre Liegeois on the basis of photographs (private communication, 20 April 2000).