License, verbatimPD
The National Gallery of Art: open access image with no usage restrictions under the NGA's open access policy (openaccess=1 in the Gallery's published_images dataset).
Giuseppe Vasi, after Giuseppe Palazzi, after Paolo Posi. The Prima Macchina for the Chinea of 1761: The Salubrious Baths, 1761. National Gallery of Art, Washington.