From flickr.com comes this image from the
Newark Public Library: "Triptych mural in the second floor gallery depicts the Greek god Apollo dispensing water from the 'Fountain of Knowledge.' Commissioned in 1927 by the Friends of the Newark Public Library, the oil on canvas was painted by
R.H. Ives Gammell. After being on display for 25 years, the mural was covered over for 35 years (for reasons not known) until its 'rediscovery' in 1987. The figure on the far left is believed to be John Cotton Dana, the library's second director."
Probably "covered" due to absence of fig leaves!